64578896765 has 4 divisors (see below), whose sum is σ = 77494676124. Its totient is φ = 51663117408.

The previous prime is 64578896747. The next prime is 64578896791. The reversal of 64578896765 is 56769887546.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9753142564 + 54825754201 = 98758^2 + 234149^2 .

It is a cyclic number.

It is not a de Polignac number, because 64578896765 - 2²⁸ = 64310461309 is a prime.

It is a Duffinian number.

It is a congruent 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, 6457889672 + ... + 6457889681.

It is an arithmetic number, because the mean of its divisors is an integer number (19373669031).

Almost surely, 2^64578896765 is an apocalyptic number.

It is an amenable number.

64578896765 is a deficient number, since it is larger than the sum of its proper divisors (12915779359).

64578896765 is a wasteful number, since it uses less digits than its factorization.

64578896765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12915779358.

The product of its digits is 609638400, while the sum is 71.

The spelling of 64578896765 in words is "sixty-four billion, five hundred seventy-eight million, eight hundred ninety-six thousand, seven hundred sixty-five".