64813680722 has 18 divisors (see below), whose sum is σ = 113097656997. Its totient is φ = 27776211624.

The previous prime is 64813680671. The next prime is 64813680727. The reversal of 64813680722 is 22708631846.

It can be written as a sum of positive squares in 2 ways, for example, as 64186729201 + 626951521 = 253351^2 + 25039^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=180019.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64813680727) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2507408 + ... + 2533124.

Almost surely, 2^64813680722 is an apocalyptic number.

64813680722 is a deficient number, since it is larger than the sum of its proper divisors (48283976275).

64813680722 is an frugal number, since it uses more digits than its factorization.

64813680722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51450 (or 25726 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 47.

The spelling of 64813680722 in words is "sixty-four billion, eight hundred thirteen million, six hundred eighty thousand, seven hundred twenty-two".