521399863 has 2 divisors, whose sum is σ = 521399864. Its totient is φ = 521399862.

The previous prime is 521399833. The next prime is 521399869. The reversal of 521399863 is 368993125.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 521399863 - 2¹⁷ = 521268791 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (521399869) 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, 260699931 + 260699932.

It is an arithmetic number, because the mean of its divisors is an integer number (260699932).

Almost surely, 2^521399863 is an apocalyptic number.

521399863 is a deficient number, since it is larger than the sum of its proper divisors (1).

521399863 is an equidigital number, since it uses as much as digits as its factorization.

521399863 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 349920, while the sum is 46.

The square root of 521399863 is about 22834.1818990740. The cubic root of 521399863 is about 804.8661032653.

The spelling of 521399863 in words is "five hundred twenty-one million, three hundred ninety-nine thousand, eight hundred sixty-three".