20640402004464 has 60 divisors (see below), whose sum is σ = 63015772791192. Its totient is φ = 6254667273600.

The previous prime is 20640402004447. The next prime is 20640402004489. The reversal of 20640402004464 is 46440020404602.

20640402004464 is a `hidden beast` number, since 2 + 0 + 6 + 4 + 0 + 4 + 0 + 200 + 446 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6515276827 + ... + 6515279994.

Almost surely, 2^{20640402004464} is an apocalyptic number.

20640402004464 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20640402004464 is an abundant number, since it is smaller than the sum of its proper divisors (42375370786728).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20640402004464 is a wasteful number, since it uses less digits than its factorization.

20640402004464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13030556846 (or 13030556837 counting only the distinct ones).

The product of its (nonzero) digits is 147456, while the sum is 36.

The spelling of 20640402004464 in words is "twenty trillion, six hundred forty billion, four hundred two million, four thousand, four hundred sixty-four".