12122640 has 120 divisors (see below), whose sum is σ = 41347800. Its totient is φ = 3182592.

The previous prime is 12122639. The next prime is 12122641. The reversal of 12122640 is 4622121.

12122640 is a `hidden beast` number, since 1 + 2 + 1 + 22 + 640 = 666.

It is an interprime number because it is at equal distance from previous prime (12122639) and next prime (12122641).

It can be written as a sum of positive squares in 4 ways, for example, as 589824 + 11532816 = 768^2 + 3396^2 .

It is a tau number, because it is divible by the number of its divisors (120).

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 (12122641) 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 23 ways as a sum of consecutive naturals, for example, 81286 + ... + 81434.

It is an arithmetic number, because the mean of its divisors is an integer number (344565).

Almost surely, 2^12122640 is an apocalyptic number.

12122640 is a gapful number since it is divisible by the number (10) 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 12122640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20673900).

12122640 is an abundant number, since it is smaller than the sum of its proper divisors (29225160).

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

12122640 is a wasteful number, since it uses less digits than its factorization.

12122640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 281 (or 272 counting only the distinct ones).

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

The square root of 12122640 is about 3481.7581765539. The cubic root of 12122640 is about 229.7201384967.

Adding to 12122640 its reverse (4622121), we get a palindrome (16744761).

The spelling of 12122640 in words is "twelve million, one hundred twenty-two thousand, six hundred forty".