257989666 has 24 divisors (see below), whose sum is σ = 443866752. Its totient is φ = 112167000.

The previous prime is 257989663. The next prime is 257989703. The reversal of 257989666 is 666989752.

It is a self number, because there is not a number n which added to its sum of digits gives 257989666.

It is not an unprimeable number, because it can be changed into a prime (257989663) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17610 + ... + 28741.

It is an arithmetic number, because the mean of its divisors is an integer number (18494448).

Almost surely, 2^257989666 is an apocalyptic number.

257989666 is a deficient number, since it is larger than the sum of its proper divisors (185877086).

257989666 is a wasteful number, since it uses less digits than its factorization.

257989666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46398 (or 46387 counting only the distinct ones).

The product of its digits is 9797760, while the sum is 58.

The square root of 257989666 is about 16062.0567176187. The cubic root of 257989666 is about 636.6011762843.

The spelling of 257989666 in words is "two hundred fifty-seven million, nine hundred eighty-nine thousand, six hundred sixty-six".