257207540 has 12 divisors (see below), whose sum is σ = 540135876. Its totient is φ = 102883008.

The previous prime is 257207539. The next prime is 257207557. The reversal of 257207540 is 45702752.

It can be written as a sum of positive squares in 2 ways, for example, as 63329764 + 193877776 = 7958^2 + 13924^2 .

It is a junction number, because it is equal to n+sod(n) for n = 257207497 and 257207506.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6430169 + ... + 6430208.

It is an arithmetic number, because the mean of its divisors is an integer number (45011323).

Almost surely, 2^257207540 is an apocalyptic number.

257207540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

257207540 is an abundant number, since it is smaller than the sum of its proper divisors (282928336).

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

257207540 is a wasteful number, since it uses less digits than its factorization.

257207540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12860386 (or 12860384 counting only the distinct ones).

The product of its (nonzero) digits is 19600, while the sum is 32.

The square root of 257207540 is about 16037.6912303486. The cubic root of 257207540 is about 635.9572146633.

The spelling of 257207540 in words is "two hundred fifty-seven million, two hundred seven thousand, five hundred forty".