64664432635021 has 16 divisors (see below), whose sum is σ = 66489866634240. Its totient is φ = 62850834334080.

The previous prime is 64664432635003. The next prime is 64664432635037. The reversal of 64664432635021 is 12053623446646.

It is not a de Polignac number, because 64664432635021 - 2⁹ = 64664432634509 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 64664432635021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64664432135021) 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, 489434056 + ... + 489566158.

It is an arithmetic number, because the mean of its divisors is an integer number (4155616664640).

Almost surely, 2^{64664432635021} is an apocalyptic number.

It is an amenable number.

64664432635021 is a deficient number, since it is larger than the sum of its proper divisors (1825433999219).

64664432635021 is a wasteful number, since it uses less digits than its factorization.

64664432635021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 176796.

The product of its (nonzero) digits is 14929920, while the sum is 52.

The spelling of 64664432635021 in words is "sixty-four trillion, six hundred sixty-four billion, four hundred thirty-two million, six hundred thirty-five thousand, twenty-one".