521121919 has 2 divisors, whose sum is σ = 521121920. Its totient is φ = 521121918.

The previous prime is 521121883. The next prime is 521121929. The reversal of 521121919 is 919121125.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 521121919 - 2⁹ = 521121407 is a prime.

It is a super-2 number, since 2×521121919² = 543136108924485122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (521121929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260560959 + 260560960.

It is an arithmetic number, because the mean of its divisors is an integer number (260560960).

Almost surely, 2^521121919 is an apocalyptic number.

521121919 is a deficient number, since it is larger than the sum of its proper divisors (1).

521121919 is an equidigital number, since it uses as much as digits as its factorization.

521121919 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1620, while the sum is 31.

The square root of 521121919 is about 22828.0949489877. The cubic root of 521121919 is about 804.7230604795.

The spelling of 521121919 in words is "five hundred twenty-one million, one hundred twenty-one thousand, nine hundred nineteen".