6640936869 has 12 divisors (see below), whose sum is σ = 10120091936. Its totient is φ = 3794607672.

The previous prime is 6640936853. The next prime is 6640936903. The reversal of 6640936869 is 9686390466.

It is not a de Polignac number, because 6640936869 - 2⁴ = 6640936853 is a prime.

It is a super-2 number, since 2×6640936869² = 88204084996087046322, which 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 (6640936849) 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, 364552 + ... + 382334.

Almost surely, 2^6640936869 is an apocalyptic number.

It is an amenable number.

6640936869 is a deficient number, since it is larger than the sum of its proper divisors (3479155067).

6640936869 is an frugal number, since it uses more digits than its factorization.

6640936869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35576 (or 17793 counting only the distinct ones).

The product of its (nonzero) digits is 10077696, while the sum is 57.

The square root of 6640936869 is about 81491.9435833997. The cubic root of 6640936869 is about 1879.6476694689.

The spelling of 6640936869 in words is "six billion, six hundred forty million, nine hundred thirty-six thousand, eight hundred sixty-nine".