20872020645 has 72 divisors (see below), whose sum is σ = 42306001920. Its totient is φ = 9491348160.

The previous prime is 20872020629. The next prime is 20872020739. The reversal of 20872020645 is 54602027802.

20872020645 is a `hidden beast` number, since 2 + 0 + 8 + 7 + 2 + 0 + 2 + 0 + 645 = 666.

It is not a de Polignac number, because 20872020645 - 2⁴ = 20872020629 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 396376 + ... + 445934.

It is an arithmetic number, because the mean of its divisors is an integer number (587583360).

Almost surely, 2^20872020645 is an apocalyptic number.

It is an amenable number.

20872020645 is an abundant number, since it is smaller than the sum of its proper divisors (21433981275).

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

20872020645 is a wasteful number, since it uses less digits than its factorization.

20872020645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49775 (or 49765 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 36.

The spelling of 20872020645 in words is "twenty billion, eight hundred seventy-two million, twenty thousand, six hundred forty-five".