20781487584576 has 84 divisors (see below), whose sum is σ = 59567615494452. Its totient is φ = 6927019075584.

The previous prime is 20781487584527. The next prime is 20781487584631. The reversal of 20781487584576 is 67548578418702.

20781487584576 is a `hidden beast` number, since 2 + 0 + 7 + 8 + 1 + 48 + 7 + 5 + 8 + 4 + 576 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 7757472730176 + 13024014854400 = 2785224^2 + 3608880^2 .

It is a Harshad number since it is a multiple of its sum of digits (72).

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, 29542740 + ... + 30237996.

Almost surely, 2^{20781487584576} is an apocalyptic number.

It is an amenable number.

20781487584576 is an abundant number, since it is smaller than the sum of its proper divisors (38786127909876).

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

20781487584576 is a wasteful number, since it uses less digits than its factorization.

20781487584576 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 747168 (or 747155 counting only the distinct ones).

The product of its (nonzero) digits is 842956800, while the sum is 72.

The spelling of 20781487584576 in words is "twenty trillion, seven hundred eighty-one billion, four hundred eighty-seven million, five hundred eighty-four thousand, five hundred seventy-six".