521998313 has 2 divisors, whose sum is σ = 521998314. Its totient is φ = 521998312.

The previous prime is 521998307. The next prime is 521998417. The reversal of 521998313 is 313899125.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 461734144 + 60264169 = 21488^2 + 7763^2 .

It is a cyclic number.

It is not a de Polignac number, because 521998313 - 2⁴ = 521998297 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (521598313) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260999156 + 260999157.

It is an arithmetic number, because the mean of its divisors is an integer number (260999157).

Almost surely, 2^521998313 is an apocalyptic number.

It is an amenable number.

521998313 is a deficient number, since it is larger than the sum of its proper divisors (1).

521998313 is an equidigital number, since it uses as much as digits as its factorization.

521998313 is an evil number, because the sum of its binary digits is even.

The product of its digits is 58320, while the sum is 41.

The square root of 521998313 is about 22847.2823985699. The cubic root of 521998313 is about 805.1739207308.

The spelling of 521998313 in words is "five hundred twenty-one million, nine hundred ninety-eight thousand, three hundred thirteen".