642365665 has 16 divisors (see below), whose sum is σ = 778377600. Its totient is φ = 508892032.

The previous prime is 642365639. The next prime is 642365681. The reversal of 642365665 is 566563246.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642365665 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 234021 + ... + 236749.

It is an arithmetic number, because the mean of its divisors is an integer number (48648600).

Almost surely, 2^642365665 is an apocalyptic number.

It is an amenable number.

642365665 is a deficient number, since it is larger than the sum of its proper divisors (136011935).

642365665 is a wasteful number, since it uses less digits than its factorization.

642365665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3176.

The product of its digits is 777600, while the sum is 43.

The square root of 642365665 is about 25344.9337146500. The cubic root of 642365665 is about 862.8343768272.

The spelling of 642365665 in words is "six hundred forty-two million, three hundred sixty-five thousand, six hundred sixty-five".