256320136 has 16 divisors (see below), whose sum is σ = 480923100. Its totient is φ = 128073984.

The previous prime is 256320107. The next prime is 256320139. The reversal of 256320136 is 631023652.

It can be written as a sum of positive squares in 2 ways, for example, as 256320100 + 36 = 16010^2 + 6^2 .

It is not an unprimeable number, because it can be changed into a prime (256320139) 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, 2916 + ... + 22828.

Almost surely, 2^256320136 is an apocalyptic number.

It is an amenable number.

256320136 is a deficient number, since it is larger than the sum of its proper divisors (224602964).

256320136 is a wasteful number, since it uses less digits than its factorization.

256320136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21528 (or 21524 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 28.

The square root of 256320136 is about 16010.0011242973. The cubic root of 256320136 is about 635.2249898169.

Adding to 256320136 its reverse (631023652), we get a palindrome (887343788).

It can be divided in two parts, 2563201 and 36, that multiplied together give a square (92275236 = 9606²).

The spelling of 256320136 in words is "two hundred fifty-six million, three hundred twenty thousand, one hundred thirty-six".