513213921 has 32 divisors (see below), whose sum is σ = 873100800. Its totient is φ = 294665040.

The previous prime is 513213917. The next prime is 513213937. The reversal of 513213921 is 129312315.

It is not a de Polignac number, because 513213921 - 2² = 513213917 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (513213971) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 39831 + ... + 51116.

It is an arithmetic number, because the mean of its divisors is an integer number (27284400).

Almost surely, 2^513213921 is an apocalyptic number.

It is an amenable number.

513213921 is a deficient number, since it is larger than the sum of its proper divisors (359886879).

513213921 is a wasteful number, since it uses less digits than its factorization.

513213921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90986 (or 90980 counting only the distinct ones).

The product of its digits is 1620, while the sum is 27.

The square root of 513213921 is about 22654.2252350417. The cubic root of 513213921 is about 800.6317515021.

The spelling of 513213921 in words is "five hundred thirteen million, two hundred thirteen thousand, nine hundred twenty-one".