257521379 has 4 divisors (see below), whose sum is σ = 257554584. Its totient is φ = 257488176.

The previous prime is 257521357. The next prime is 257521387. The reversal of 257521379 is 973125752.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 257521379 - 2¹⁶ = 257455843 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (257521339) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1919 + ... + 22775.

It is an arithmetic number, because the mean of its divisors is an integer number (64388646).

Almost surely, 2^257521379 is an apocalyptic number.

257521379 is a deficient number, since it is larger than the sum of its proper divisors (33205).

257521379 is a wasteful number, since it uses less digits than its factorization.

257521379 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33204.

The product of its digits is 132300, while the sum is 41.

The square root of 257521379 is about 16047.4726670588. The cubic root of 257521379 is about 636.2157698798.

The spelling of 257521379 in words is "two hundred fifty-seven million, five hundred twenty-one thousand, three hundred seventy-nine".