253521657 has 12 divisors (see below), whose sum is σ = 379761200. Its totient is φ = 169014276.

The previous prime is 253521647. The next prime is 253521659. The reversal of 253521657 is 756125352.

It is not a de Polignac number, because 253521657 - 2⁴ = 253521641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (253521659) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 521407 + ... + 521892.

Almost surely, 2^253521657 is an apocalyptic number.

253521657 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

253521657 is a deficient number, since it is larger than the sum of its proper divisors (126239543).

253521657 is an equidigital number, since it uses as much as digits as its factorization.

253521657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1043314 (or 1043302 counting only the distinct ones).

The product of its digits is 63000, while the sum is 36.

The square root of 253521657 is about 15922.3634238137. The cubic root of 253521657 is about 632.9047497119.

The spelling of 253521657 in words is "two hundred fifty-three million, five hundred twenty-one thousand, six hundred fifty-seven".