256931136 has 224 divisors, whose sum is σ = 942197760. Its totient is φ = 66700800.

The previous prime is 256931117. The next prime is 256931153. The reversal of 256931136 is 631139652.

It is a tau number, because it is divible by the number of its divisors (224).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 256931136.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 132091 + ... + 134021.

It is an arithmetic number, because the mean of its divisors is an integer number (4206240).

Almost surely, 2^256931136 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256931136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (471098880).

256931136 is an abundant number, since it is smaller than the sum of its proper divisors (685266624).

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

256931136 is a wasteful number, since it uses less digits than its factorization.

256931136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1970 (or 1954 counting only the distinct ones).

The product of its digits is 29160, while the sum is 36.

The square root of 256931136 is about 16029.0715888351. The cubic root of 256931136 is about 635.7293259029.

The spelling of 256931136 in words is "two hundred fifty-six million, nine hundred thirty-one thousand, one hundred thirty-six".