257456720 has 20 divisors (see below), whose sum is σ = 598587060. Its totient is φ = 102982656.

The previous prime is 257456713. The next prime is 257456723. The reversal of 257456720 is 27654752.

It is a happy number.

257456720 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 26173456 + 231283264 = 5116^2 + 15208^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257456723) 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, 1609025 + ... + 1609184.

It is an arithmetic number, because the mean of its divisors is an integer number (29929353).

Almost surely, 2^257456720 is an apocalyptic number.

257456720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

257456720 is an abundant number, since it is smaller than the sum of its proper divisors (341130340).

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

257456720 is a wasteful number, since it uses less digits than its factorization.

257456720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3218222 (or 3218216 counting only the distinct ones).

The product of its (nonzero) digits is 117600, while the sum is 38.

The square root of 257456720 is about 16045.4579242850. The cubic root of 257456720 is about 636.1625179659.

The spelling of 257456720 in words is "two hundred fifty-seven million, four hundred fifty-six thousand, seven hundred twenty".