6646739409 has 12 divisors (see below), whose sum is σ = 9626182800. Its totient is φ = 4419465624.

The previous prime is 6646739399. The next prime is 6646739417. The reversal of 6646739409 is 9049376466.

It is not a de Polignac number, because 6646739409 - 2²⁰ = 6645690833 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (6646735409) 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, 970899 + ... + 977720.

It is an arithmetic number, because the mean of its divisors is an integer number (802181900).

Almost surely, 2^6646739409 is an apocalyptic number.

It is an amenable number.

6646739409 is a deficient number, since it is larger than the sum of its proper divisors (2979443391).

6646739409 is a wasteful number, since it uses less digits than its factorization.

6646739409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1949004 (or 1949001 counting only the distinct ones).

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

The square root of 6646739409 is about 81527.5377341914. The cubic root of 6646739409 is about 1880.1949595047.

The spelling of 6646739409 in words is "six billion, six hundred forty-six million, seven hundred thirty-nine thousand, four hundred nine".