6399043531 has 2 divisors, whose sum is σ = 6399043532. Its totient is φ = 6399043530.

The previous prime is 6399043487. The next prime is 6399043577. The reversal of 6399043531 is 1353409936.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6399043531 - 2²⁵ = 6365489099 is a prime.

It is a super-2 number, since 2×6399043531² = 81895516223265895922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (6399743531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3199521765 + 3199521766.

It is an arithmetic number, because the mean of its divisors is an integer number (3199521766).

Almost surely, 2^6399043531 is an apocalyptic number.

6399043531 is a deficient number, since it is larger than the sum of its proper divisors (1).

6399043531 is an equidigital number, since it uses as much as digits as its factorization.

6399043531 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 262440, while the sum is 43.

The square root of 6399043531 is about 79994.0218453854. The cubic root of 6399043531 is about 1856.5430385074.

The spelling of 6399043531 in words is "six billion, three hundred ninety-nine million, forty-three thousand, five hundred thirty-one".