521997 has 24 divisors (see below), whose sum is σ = 837216. Its totient is φ = 288288.

The previous prime is 521993. The next prime is 521999. The reversal of 521997 is 799125.

It is not a de Polignac number, because 521997 - 2² = 521993 is a prime.

521997 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521993) 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 23 ways as a sum of consecutive naturals, for example, 7758 + ... + 7824.

It is an arithmetic number, because the mean of its divisors is an integer number (34884).

2⁵²¹⁹⁹⁷ is an apocalyptic number.

It is an amenable number.

521997 is a deficient number, since it is larger than the sum of its proper divisors (315219).

521997 is a wasteful number, since it uses less digits than its factorization.

521997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137 (or 130 counting only the distinct ones).

The product of its digits is 5670, while the sum is 33.

The square root of 521997 is about 722.4935985876. The cubic root of 521997 is about 80.5173245637.

The spelling of 521997 in words is "five hundred twenty-one thousand, nine hundred ninety-seven".