257330640 has 160 divisors (see below), whose sum is σ = 931368960. Its totient is φ = 57549312.

The previous prime is 257330639. The next prime is 257330641. The reversal of 257330640 is 46033752.

It is an interprime number because it is at equal distance from previous prime (257330639) and next prime (257330641).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 257330598 and 257330607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257330641) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 77331 + ... + 80589.

It is an arithmetic number, because the mean of its divisors is an integer number (5821056).

Almost surely, 2^257330640 is an apocalyptic number.

257330640 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 257330640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (465684480).

257330640 is an abundant number, since it is smaller than the sum of its proper divisors (674038320).

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

257330640 is a wasteful number, since it uses less digits than its factorization.

257330640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3329 (or 3323 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 30.

The square root of 257330640 is about 16041.5286054665. The cubic root of 257330640 is about 636.0586552446.

The spelling of 257330640 in words is "two hundred fifty-seven million, three hundred thirty thousand, six hundred forty".