521957 has 4 divisors (see below), whose sum is σ = 527436. Its totient is φ = 516480.

The previous prime is 521929. The next prime is 521981. The reversal of 521957 is 759125.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 201601 + 320356 = 449^2 + 566^2 .

It is a cyclic number.

It is not a de Polignac number, because 521957 - 2¹² = 517861 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521357) 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, 2594 + ... + 2787.

It is an arithmetic number, because the mean of its divisors is an integer number (131859).

2⁵²¹⁹⁵⁷ is an apocalyptic number.

It is an amenable number.

521957 is a deficient number, since it is larger than the sum of its proper divisors (5479).

521957 is an equidigital number, since it uses as much as digits as its factorization.

521957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5478.

The product of its digits is 3150, while the sum is 29.

The square root of 521957 is about 722.4659161511. The cubic root of 521957 is about 80.5152678627.

The spelling of 521957 in words is "five hundred twenty-one thousand, nine hundred fifty-seven".