64686868646 has 32 divisors (see below), whose sum is σ = 103551354720. Its totient is φ = 30219264000.

The previous prime is 64686868643. The next prime is 64686868663.

It is a happy number.

64686868646 is nontrivially palindromic in base 10.

64686868646 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64686868643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 953576 + ... + 1019156.

It is an arithmetic number, because the mean of its divisors is an integer number (3235979835).

Almost surely, 2^64686868646 is an apocalyptic number.

64686868646 is a deficient number, since it is larger than the sum of its proper divisors (38864486074).

64686868646 is a wasteful number, since it uses less digits than its factorization.

64686868646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65960.

The product of its digits is 382205952, while the sum is 68.

The spelling of 64686868646 in words is "sixty-four billion, six hundred eighty-six million, eight hundred sixty-eight thousand, six hundred forty-six".