6400039999 has 2 divisors, whose sum is σ = 6400040000. Its totient is φ = 6400039998.

The previous prime is 6400039991. The next prime is 6400040041. The reversal of 6400039999 is 9999300046.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6400039999 - 2³ = 6400039991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6400039991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3200019999 + 3200020000.

It is an arithmetic number, because the mean of its divisors is an integer number (3200020000).

Almost surely, 2^6400039999 is an apocalyptic number.

6400039999 is a deficient number, since it is larger than the sum of its proper divisors (1).

6400039999 is an equidigital number, since it uses as much as digits as its factorization.

6400039999 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 472392, while the sum is 49.

The square root of 6400039999 is about 80000.2499933594. The cubic root of 6400039999 is about 1856.6394013310.

The spelling of 6400039999 in words is "six billion, four hundred million, thirty-nine thousand, nine hundred ninety-nine".