257249664 has 384 divisors, whose sum is σ = 941990400. Its totient is φ = 65691648.

The previous prime is 257249647. The next prime is 257249711. The reversal of 257249664 is 466942752.

It is a tau number, because it is divible by the number of its divisors (384).

It is a super-3 number, since 3×257249664³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3523932 + ... + 3524004.

It is an arithmetic number, because the mean of its divisors is an integer number (2453100).

Almost surely, 2^257249664 is an apocalyptic number.

257249664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 257249664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (470995200).

257249664 is an abundant number, since it is smaller than the sum of its proper divisors (684740736).

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

257249664 is a wasteful number, since it uses less digits than its factorization.

257249664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142 (or 127 counting only the distinct ones).

The product of its digits is 725760, while the sum is 45.

The square root of 257249664 is about 16039.0044578833. The cubic root of 257249664 is about 635.9919305966.

The spelling of 257249664 in words is "two hundred fifty-seven million, two hundred forty-nine thousand, six hundred sixty-four".