6399760243221 has 24 divisors (see below), whose sum is σ = 9319816303616. Its totient is φ = 4231701182880.

The previous prime is 6399760243189. The next prime is 6399760243231. The reversal of 6399760243221 is 1223420679936.

6399760243221 is a `hidden beast` number, since 6 + 3 + 9 + 9 + 7 + 602 + 4 + 3 + 2 + 21 = 666.

It is not a de Polignac number, because 6399760243221 - 2⁵ = 6399760243189 is a prime.

It is a super-2 number, since 2×6399760243221² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6399760243231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5339350 + ... + 6427143.

Almost surely, 2^{6399760243221} is an apocalyptic number.

It is an amenable number.

6399760243221 is a deficient number, since it is larger than the sum of its proper divisors (2920056060395).

6399760243221 is a wasteful number, since it uses less digits than its factorization.

6399760243221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11766993 (or 11766990 counting only the distinct ones).

The product of its (nonzero) digits is 5878656, while the sum is 54.

The spelling of 6399760243221 in words is "six trillion, three hundred ninety-nine billion, seven hundred sixty million, two hundred forty-three thousand, two hundred twenty-one".