257155668 has 288 divisors, whose sum is σ = 891233280. Its totient is φ = 62277120.

The previous prime is 257155667. The next prime is 257155693. The reversal of 257155668 is 866551752.

257155668 is a `hidden beast` number, since 25 + 71 + 556 + 6 + 8 = 666.

It is a super-2 number, since 2×257155668² = 132258075169052448, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257155667) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2403271 + ... + 2403377.

It is an arithmetic number, because the mean of its divisors is an integer number (3094560).

Almost surely, 2^257155668 is an apocalyptic number.

257155668 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 257155668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (445616640).

257155668 is an abundant number, since it is smaller than the sum of its proper divisors (634077612).

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

257155668 is a wasteful number, since it uses less digits than its factorization.

257155668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172 (or 147 counting only the distinct ones).

The product of its digits is 504000, while the sum is 45.

The square root of 257155668 is about 16036.0739584226. The cubic root of 257155668 is about 635.9144598377.

The spelling of 257155668 in words is "two hundred fifty-seven million, one hundred fifty-five thousand, six hundred sixty-eight".