257129715864 has 128 divisors (see below), whose sum is σ = 743272611840. Its totient is φ = 72608441472.

The previous prime is 257129715827. The next prime is 257129715881. The reversal of 257129715864 is 468517921752.

It is a super-2 number, since 2×257129715864² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5588457 + ... + 5634279.

It is an arithmetic number, because the mean of its divisors is an integer number (5806817280).

Almost surely, 2^257129715864 is an apocalyptic number.

257129715864 is a gapful number since it is divisible by the number (24) 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 257129715864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (371636305920).

257129715864 is an abundant number, since it is smaller than the sum of its proper divisors (486142895976).

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

257129715864 is a wasteful number, since it uses less digits than its factorization.

257129715864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46229 (or 46225 counting only the distinct ones).

The product of its digits is 8467200, while the sum is 57.

The spelling of 257129715864 in words is "two hundred fifty-seven billion, one hundred twenty-nine million, seven hundred fifteen thousand, eight hundred sixty-four".