20684894672 has 20 divisors (see below), whose sum is σ = 43159828740. Its totient is φ = 9546874368.

The previous prime is 20684894663. The next prime is 20684894719. The reversal of 20684894672 is 27649848602.

It can be written as a sum of positive squares in 2 ways, for example, as 13104754576 + 7580140096 = 114476^2 + 87064^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49723097 + ... + 49723512.

It is an arithmetic number, because the mean of its divisors is an integer number (2157991437).

Almost surely, 2^20684894672 is an apocalyptic number.

It is an amenable number.

20684894672 is an abundant number, since it is smaller than the sum of its proper divisors (22474934068).

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

20684894672 is a wasteful number, since it uses less digits than its factorization.

20684894672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99446630 (or 99446624 counting only the distinct ones).

The product of its (nonzero) digits is 9289728, while the sum is 56.

The spelling of 20684894672 in words is "twenty billion, six hundred eighty-four million, eight hundred ninety-four thousand, six hundred seventy-two".