521121913 has 8 divisors (see below), whose sum is σ = 569585408. Its totient is φ = 473855184.

The previous prime is 521121883. The next prime is 521121919. The reversal of 521121913 is 319121125.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 521121913 - 2⁹ = 521121401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (521121919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 298281 + ... + 300022.

It is an arithmetic number, because the mean of its divisors is an integer number (71198176).

Almost surely, 2^521121913 is an apocalyptic number.

It is an amenable number.

521121913 is a deficient number, since it is larger than the sum of its proper divisors (48463495).

521121913 is a wasteful number, since it uses less digits than its factorization.

521121913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 598383.

The product of its digits is 540, while the sum is 25.

The square root of 521121913 is about 22828.0948175707. The cubic root of 521121913 is about 804.7230573910.

The spelling of 521121913 in words is "five hundred twenty-one million, one hundred twenty-one thousand, nine hundred thirteen".