520164921 has 4 divisors (see below), whose sum is σ = 693553232. Its totient is φ = 346776612.

The previous prime is 520164917. The next prime is 520164959. The reversal of 520164921 is 129461025.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 520164921 - 2² = 520164917 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (520164961) 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 3 ways as a sum of consecutive naturals, for example, 86694151 + ... + 86694156.

It is an arithmetic number, because the mean of its divisors is an integer number (173388308).

Almost surely, 2^520164921 is an apocalyptic number.

It is an amenable number.

520164921 is a deficient number, since it is larger than the sum of its proper divisors (173388311).

520164921 is a wasteful number, since it uses less digits than its factorization.

520164921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173388310.

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 520164921 is about 22807.1243474490. The cubic root of 520164921 is about 804.2301558233.

The spelling of 520164921 in words is "five hundred twenty million, one hundred sixty-four thousand, nine hundred twenty-one".