257158440 has 192 divisors, whose sum is σ = 1042104960. Its totient is φ = 53429760.

The previous prime is 257158427. The next prime is 257158459. The reversal of 257158440 is 44851752.

257158440 is a `hidden beast` number, since 2 + 5 + 71 + 584 + 4 + 0 = 666.

It is a super-2 number, since 2×257158440² = 132260926526467200, which contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 257158395 and 257158404.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 23082 + ... + 32358.

It is an arithmetic number, because the mean of its divisors is an integer number (5427630).

Almost surely, 2^257158440 is an apocalyptic number.

257158440 is a gapful number since it is divisible by the number (20) 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 257158440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (521052480).

257158440 is an abundant number, since it is smaller than the sum of its proper divisors (784946520).

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

257158440 is a wasteful number, since it uses less digits than its factorization.

257158440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9312 (or 9305 counting only the distinct ones).

The product of its (nonzero) digits is 44800, while the sum is 36.

The square root of 257158440 is about 16036.1603883224. The cubic root of 257158440 is about 635.9167447683.

The spelling of 257158440 in words is "two hundred fifty-seven million, one hundred fifty-eight thousand, four hundred forty".