20521288568 has 16 divisors (see below), whose sum is σ = 41975363160. Its totient is φ = 9327858400.

The previous prime is 20521288559. The next prime is 20521288573. The reversal of 20521288568 is 86588212502.

It is a happy number.

It is a super-2 number, since 2×20521288568² (a number of 21 digits) contains 22 as substring.

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, 116598143 + ... + 116598318.

Almost surely, 2^20521288568 is an apocalyptic number.

It is an amenable number.

20521288568 is an abundant number, since it is smaller than the sum of its proper divisors (21454074592).

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

20521288568 is a wasteful number, since it uses less digits than its factorization.

20521288568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 233196478 (or 233196474 counting only the distinct ones).

The product of its (nonzero) digits is 614400, while the sum is 47.

The spelling of 20521288568 in words is "twenty billion, five hundred twenty-one million, two hundred eighty-eight thousand, five hundred sixty-eight".