256171572 has 144 divisors (see below), whose sum is σ = 731989440. Its totient is φ = 78008832.

The previous prime is 256171571. The next prime is 256171607. The reversal of 256171572 is 275171652.

256171572 is a `hidden beast` number, since 25 + 61 + 7 + 1 + 572 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256171571) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 611179 + ... + 611597.

It is an arithmetic number, because the mean of its divisors is an integer number (5083260).

Almost surely, 2^256171572 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 256171572, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (365994720).

256171572 is an abundant number, since it is smaller than the sum of its proper divisors (475817868).

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

256171572 is a wasteful number, since it uses less digits than its factorization.

256171572 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 492 (or 478 counting only the distinct ones).

The product of its digits is 29400, while the sum is 36.

The square root of 256171572 is about 16005.3607269565. The cubic root of 256171572 is about 635.1022399289.

The spelling of 256171572 in words is "two hundred fifty-six million, one hundred seventy-one thousand, five hundred seventy-two".