20270640 has 160 divisors (see below), whose sum is σ = 69370560. Its totient is φ = 4866048.

The previous prime is 20270629. The next prime is 20270641. The reversal of 20270640 is 4607202.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (20270641) 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 31 ways as a sum of consecutive naturals, for example, 227716 + ... + 227804.

It is an arithmetic number, because the mean of its divisors is an integer number (433566).

Almost surely, 2^20270640 is an apocalyptic number.

20270640 is a gapful number since it is divisible by the number (20) 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 20270640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34685280).

20270640 is an abundant number, since it is smaller than the sum of its proper divisors (49099920).

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

20270640 is a wasteful number, since it uses less digits than its factorization.

20270640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191 (or 185 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 21.

The square root of 20270640 is about 4502.2927492557. The cubic root of 20270640 is about 272.6606633290.

Adding to 20270640 its reverse (4607202), we get a palindrome (24877842).

It can be divided in two parts, 20270 and 640, that added together give a triangular number (20910 = T₂₀₄).

The spelling of 20270640 in words is "twenty million, two hundred seventy thousand, six hundred forty".