257720560 has 40 divisors (see below), whose sum is σ = 630740880. Its totient is φ = 97661952.

The previous prime is 257720549. The next prime is 257720563. The reversal of 257720560 is 65027752.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257720563) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 83257 + ... + 86296.

It is an arithmetic number, because the mean of its divisors is an integer number (15768522).

Almost surely, 2^257720560 is an apocalyptic number.

257720560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

257720560 is an abundant number, since it is smaller than the sum of its proper divisors (373020320).

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

257720560 is a wasteful number, since it uses less digits than its factorization.

257720560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169585 (or 169579 counting only the distinct ones).

The product of its (nonzero) digits is 29400, while the sum is 34.

The square root of 257720560 is about 16053.6774603204. The cubic root of 257720560 is about 636.3797555348.

The spelling of 257720560 in words is "two hundred fifty-seven million, seven hundred twenty thousand, five hundred sixty".