6399994671 has 96 divisors (see below), whose sum is σ = 11251408896. Its totient is φ = 3428352000.

The previous prime is 6399994663. The next prime is 6399994691. The reversal of 6399994671 is 1764999936.

It is not a de Polignac number, because 6399994671 - 2³ = 6399994663 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a junction number, because it is equal to n+sod(n) for n = 6399994599 and 6399994608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6399994621) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 20578606 + ... + 20578916.

It is an arithmetic number, because the mean of its divisors is an integer number (117202176).

Almost surely, 2^6399994671 is an apocalyptic number.

6399994671 is a deficient number, since it is larger than the sum of its proper divisors (4851414225).

6399994671 is a wasteful number, since it uses less digits than its factorization.

6399994671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 653 (or 650 counting only the distinct ones).

The product of its digits is 19840464, while the sum is 63.

The square root of 6399994671 is about 79999.9666937431. The cubic root of 6399994671 is about 1856.6350181319.

The spelling of 6399994671 in words is "six billion, three hundred ninety-nine million, nine hundred ninety-four thousand, six hundred seventy-one".