6409942665 has 32 divisors (see below), whose sum is σ = 12006925056. Its totient is φ = 2858787840.

The previous prime is 6409942661. The next prime is 6409942681. The reversal of 6409942665 is 5662499046.

It is a happy number.

It is not a de Polignac number, because 6409942665 - 2² = 6409942661 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6409942661) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 740172 + ... + 748781.

It is an arithmetic number, because the mean of its divisors is an integer number (375216408).

Almost surely, 2^6409942665 is an apocalyptic number.

It is an amenable number.

6409942665 is a deficient number, since it is larger than the sum of its proper divisors (5596982391).

6409942665 is a wasteful number, since it uses less digits than its factorization.

6409942665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1489009.

The product of its (nonzero) digits is 2799360, while the sum is 51.

The square root of 6409942665 is about 80062.1175400701. The cubic root of 6409942665 is about 1857.5964893810.

The spelling of 6409942665 in words is "six billion, four hundred nine million, nine hundred forty-two thousand, six hundred sixty-five".