257239644 has 12 divisors (see below), whose sum is σ = 600225864. Its totient is φ = 85746544.

The previous prime is 257239639. The next prime is 257239649. The reversal of 257239644 is 446932752.

It is an interprime number because it is at equal distance from previous prime (257239639) and next prime (257239649).

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 257239596 and 257239605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257239649) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10718307 + ... + 10718330.

It is an arithmetic number, because the mean of its divisors is an integer number (50018822).

Almost surely, 2^257239644 is an apocalyptic number.

It is an amenable number.

257239644 is an abundant number, since it is smaller than the sum of its proper divisors (342986220).

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

257239644 is a wasteful number, since it uses less digits than its factorization.

257239644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21436644 (or 21436642 counting only the distinct ones).

The product of its digits is 362880, while the sum is 42.

The square root of 257239644 is about 16038.6920913147. The cubic root of 257239644 is about 635.9836730906.

The spelling of 257239644 in words is "two hundred fifty-seven million, two hundred thirty-nine thousand, six hundred forty-four".