257679540 has 144 divisors (see below), whose sum is σ = 836402112. Its totient is φ = 63986688.

The previous prime is 257679503. The next prime is 257679589. The reversal of 257679540 is 45976752.

257679540 is a `hidden beast` number, since 2 + 576 + 79 + 5 + 4 + 0 = 666.

It is a super-2 number, since 2×257679540² = 132797490669223200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

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, 327027 + ... + 327813.

It is an arithmetic number, because the mean of its divisors is an integer number (5808348).

Almost surely, 2^257679540 is an apocalyptic number.

257679540 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 257679540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (418201056).

257679540 is an abundant number, since it is smaller than the sum of its proper divisors (578722572).

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

257679540 is a wasteful number, since it uses less digits than its factorization.

257679540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 926 (or 921 counting only the distinct ones).

The product of its (nonzero) digits is 529200, while the sum is 45.

The square root of 257679540 is about 16052.3998205876. The cubic root of 257679540 is about 636.3459906919.

The spelling of 257679540 in words is "two hundred fifty-seven million, six hundred seventy-nine thousand, five hundred forty".