256633220 has 12 divisors (see below), whose sum is σ = 538929804. Its totient is φ = 102653280.

The previous prime is 256633213. The next prime is 256633229. The reversal of 256633220 is 22336652.

It can be written as a sum of positive squares in 2 ways, for example, as 200052736 + 56580484 = 14144^2 + 7522^2 .

It is not an unprimeable number, because it can be changed into a prime (256633229) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6415811 + ... + 6415850.

It is an arithmetic number, because the mean of its divisors is an integer number (44910817).

Almost surely, 2^256633220 is an apocalyptic number.

256633220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

256633220 is an abundant number, since it is smaller than the sum of its proper divisors (282296584).

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

256633220 is a wasteful number, since it uses less digits than its factorization.

256633220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12831670 (or 12831668 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 29.

The square root of 256633220 is about 16019.7759035512. The cubic root of 256633220 is about 635.4835179018.

Adding to 256633220 its reverse (22336652), we get a palindrome (278969872).

The spelling of 256633220 in words is "two hundred fifty-six million, six hundred thirty-three thousand, two hundred twenty".