64655572765 has 24 divisors (see below), whose sum is σ = 90474711480. Its totient is φ = 44226782208.

The previous prime is 64655572759. The next prime is 64655572789. The reversal of 64655572765 is 56727555646.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 33157132281 + 31498440484 = 182091^2 + 177478^2 .

It is not a de Polignac number, because 64655572765 - 2⁵ = 64655572733 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 222412 + ... + 422821.

It is an arithmetic number, because the mean of its divisors is an integer number (3769779645).

Almost surely, 2^64655572765 is an apocalyptic number.

It is an amenable number.

64655572765 is a deficient number, since it is larger than the sum of its proper divisors (25819138715).

64655572765 is a wasteful number, since it uses less digits than its factorization.

64655572765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 645661 (or 645654 counting only the distinct ones).

The product of its digits is 52920000, while the sum is 58.

The spelling of 64655572765 in words is "sixty-four billion, six hundred fifty-five million, five hundred seventy-two thousand, seven hundred sixty-five".