257720616 has 80 divisors (see below), whose sum is σ = 724257600. Its totient is φ = 85621536.

The previous prime is 257720563. The next prime is 257720621. The reversal of 257720616 is 616027752.

257720616 is a `hidden beast` number, since 2 + 577 + 20 + 61 + 6 = 666.

It is a super-2 number, since 2×257720616² = 132839831822838912, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 299595 + ... + 300453.

It is an arithmetic number, because the mean of its divisors is an integer number (9053220).

Almost surely, 2^257720616 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 257720616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (362128800).

257720616 is an abundant number, since it is smaller than the sum of its proper divisors (466536984).

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

257720616 is a wasteful number, since it uses less digits than its factorization.

257720616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1340 (or 1327 counting only the distinct ones).

The product of its (nonzero) digits is 35280, while the sum is 36.

The square root of 257720616 is about 16053.6792044690. The cubic root of 257720616 is about 636.3798016277.

The spelling of 257720616 in words is "two hundred fifty-seven million, seven hundred twenty thousand, six hundred sixteen".