257716645 has 16 divisors (see below), whose sum is σ = 314751600. Its totient is φ = 202535424.

The previous prime is 257716631. The next prime is 257716663. The reversal of 257716645 is 546617752.

It can be written as a sum of positive squares in 8 ways, for example, as 370881 + 257345764 = 609^2 + 16042^2 .

It is a cyclic number.

It is not a de Polignac number, because 257716645 - 2¹³ = 257708453 is a prime.

It is a super-2 number, since 2×257716645² = 132835738220112050, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 99831 + ... + 102379.

It is an arithmetic number, because the mean of its divisors is an integer number (19671975).

Almost surely, 2^257716645 is an apocalyptic number.

It is an amenable number.

257716645 is a deficient number, since it is larger than the sum of its proper divisors (57034955).

257716645 is a wasteful number, since it uses less digits than its factorization.

257716645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2904.

The product of its digits is 352800, while the sum is 43.

The square root of 257716645 is about 16053.5555251788. Note that the first 4 decimals coincide. The cubic root of 257716645 is about 636.3765331307.

The spelling of 257716645 in words is "two hundred fifty-seven million, seven hundred sixteen thousand, six hundred forty-five".