21144671454808 has 64 divisors (see below), whose sum is σ = 46214743687200. Its totient is φ = 8962859243520.

The previous prime is 21144671454773. The next prime is 21144671454847. The reversal of 21144671454808 is 80845417644112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 64672435 + ... + 64998562.

Almost surely, 2^{21144671454808} is an apocalyptic number.

It is an amenable number.

21144671454808 is an abundant number, since it is smaller than the sum of its proper divisors (25070072232392).

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

21144671454808 is a wasteful number, since it uses less digits than its factorization.

21144671454808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129671140 (or 129671136 counting only the distinct ones).

The product of its (nonzero) digits is 6881280, while the sum is 55.

The spelling of 21144671454808 in words is "twenty-one trillion, one hundred forty-four billion, six hundred seventy-one million, four hundred fifty-four thousand, eight hundred eight".