4121640 has 72 divisors (see below), whose sum is σ = 13521690. Its totient is φ = 1088832.

The previous prime is 4121629. The next prime is 4121641. The reversal of 4121640 is 461214.

4121640 is a `hidden beast` number, since 4 + 1 + 21 + 640 = 666.

4121640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 3709476 + 412164 = 1926^2 + 642^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a hoax number, since the sum of its digits (18) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (4121641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 38467 + ... + 38573.

Almost surely, 2^4121640 is an apocalyptic number.

4121640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 4121640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6760845).

4121640 is an abundant number, since it is smaller than the sum of its proper divisors (9400050).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

4121640 is a wasteful number, since it uses less digits than its factorization.

4121640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231 (or 117 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 4121640 is about 2030.1822578281. The cubic root of 4121640 is about 160.3331599629. Note that the first 3 decimals are identical.

Adding to 4121640 its reverse (461214), we get a palindrome (4582854).

It can be divided in two parts, 4121 and 640, that added together give a square (4761 = 69²).

The spelling of 4121640 in words is "four million, one hundred twenty-one thousand, six hundred forty".