257172156 has 72 divisors (see below), whose sum is σ = 685461504. Its totient is φ = 81177120.

The previous prime is 257172143. The next prime is 257172161. The reversal of 257172156 is 651271752.

257172156 is a `hidden beast` number, since 2 + 571 + 72 + 15 + 6 = 666.

257172156 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×257172156² = 132275035643376672, which contains 22 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

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 257172156.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 50001 + ... + 54903.

Almost surely, 2^257172156 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 257172156, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (342730752).

257172156 is an abundant number, since it is smaller than the sum of its proper divisors (428289348).

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

257172156 is a wasteful number, since it uses less digits than its factorization.

257172156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4991 (or 4986 counting only the distinct ones).

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

The square root of 257172156 is about 16036.5880411015. The cubic root of 257172156 is about 635.9280504819.

The spelling of 257172156 in words is "two hundred fifty-seven million, one hundred seventy-two thousand, one hundred fifty-six".