20521913672 has 16 divisors (see below), whose sum is σ = 41438479740. Its totient is φ = 9471652416.

The previous prime is 20521913653. The next prime is 20521913723. The reversal of 20521913672 is 27631912502.

It can be written as a sum of positive squares in 2 ways, for example, as 18399837316 + 2122076356 = 135646^2 + 46066^2 .

It is a super-2 number, since 2×20521913672² (a number of 21 digits) contains 22 as substring.

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, 98662943 + ... + 98663150.

Almost surely, 2^20521913672 is an apocalyptic number.

It is an amenable number.

20521913672 is an abundant number, since it is smaller than the sum of its proper divisors (20916566068).

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

20521913672 is a wasteful number, since it uses less digits than its factorization.

20521913672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197326112 (or 197326108 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 38.

The spelling of 20521913672 in words is "twenty billion, five hundred twenty-one million, nine hundred thirteen thousand, six hundred seventy-two".