6401979 has 12 divisors (see below), whose sum is σ = 9791496. Its totient is φ = 4016832.

The previous prime is 6401977. The next prime is 6401987. The reversal of 6401979 is 9791046.

6401979 is a `hidden beast` number, since 640 + 1 + 9 + 7 + 9 = 666.

It is not a de Polignac number, because 6401979 - 2¹ = 6401977 is a prime.

6401979 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (6401971) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 20769 + ... + 21074.

It is an arithmetic number, because the mean of its divisors is an integer number (815958).

Almost surely, 2^6401979 is an apocalyptic number.

6401979 is a deficient number, since it is larger than the sum of its proper divisors (3389517).

6401979 is a wasteful number, since it uses less digits than its factorization.

6401979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41866 (or 41863 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 36.

The square root of 6401979 is about 2530.2132321210. The cubic root of 6401979 is about 185.6826882563.

The spelling of 6401979 in words is "six million, four hundred one thousand, nine hundred seventy-nine".