257721425 has 12 divisors (see below), whose sum is σ = 344157660. Its totient is φ = 190317120.

The previous prime is 257721413. The next prime is 257721427. The reversal of 257721425 is 524127752.

It can be written as a sum of positive squares in 6 ways, for example, as 99062209 + 158659216 = 9953^2 + 12596^2 .

It is not a de Polignac number, because 257721425 - 2¹⁰ = 257720401 is a prime.

It is not an unprimeable number, because it can be changed into a prime (257721427) 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 11 ways as a sum of consecutive naturals, for example, 396170 + ... + 396819.

It is an arithmetic number, because the mean of its divisors is an integer number (28679805).

Almost surely, 2^257721425 is an apocalyptic number.

257721425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

257721425 is a deficient number, since it is larger than the sum of its proper divisors (86436235).

257721425 is a wasteful number, since it uses less digits than its factorization.

257721425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 793012 (or 793007 counting only the distinct ones).

The product of its digits is 39200, while the sum is 35.

The square root of 257721425 is about 16053.7044011655. The cubic root of 257721425 is about 636.3804675047.

The spelling of 257721425 in words is "two hundred fifty-seven million, seven hundred twenty-one thousand, four hundred twenty-five".