257470640 has 80 divisors (see below), whose sum is σ = 687694080. Its totient is φ = 87816960.

The previous prime is 257470639. The next prime is 257470651. The reversal of 257470640 is 46074752.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×257470640² = 132582260924019200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 257470640.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 117071 + ... + 119249.

It is an arithmetic number, because the mean of its divisors is an integer number (8596176).

Almost surely, 2^257470640 is an apocalyptic number.

257470640 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 257470640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (343847040).

257470640 is an abundant number, since it is smaller than the sum of its proper divisors (430223440).

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

257470640 is a wasteful number, since it uses less digits than its factorization.

257470640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2410 (or 2404 counting only the distinct ones).

The product of its (nonzero) digits is 47040, while the sum is 35.

The square root of 257470640 is about 16045.8916860360. The cubic root of 257470640 is about 636.1739829643.

The spelling of 257470640 in words is "two hundred fifty-seven million, four hundred seventy thousand, six hundred forty".