64020072665 has 4 divisors (see below), whose sum is σ = 76824087204. Its totient is φ = 51216058128.

The previous prime is 64020072601. The next prime is 64020072673. The reversal of 64020072665 is 56627002046.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56627002046 = 2 ⋅28313501023.

It can be written as a sum of positive squares in 2 ways, for example, as 23209608409 + 40810464256 = 152347^2 + 202016^2 .

It is a cyclic number.

It is not a de Polignac number, because 64020072665 - 2⁶ = 64020072601 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6402007262 + ... + 6402007271.

It is an arithmetic number, because the mean of its divisors is an integer number (19206021801).

Almost surely, 2^64020072665 is an apocalyptic number.

It is an amenable number.

64020072665 is a deficient number, since it is larger than the sum of its proper divisors (12804014539).

64020072665 is a wasteful number, since it uses less digits than its factorization.

64020072665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12804014538.

The product of its (nonzero) digits is 120960, while the sum is 38.

The spelling of 64020072665 in words is "sixty-four billion, twenty million, seventy-two thousand, six hundred sixty-five".