20651701521 has 64 divisors (see below), whose sum is σ = 32039239680. Its totient is φ = 11701247040.

The previous prime is 20651701513. The next prime is 20651701607. The reversal of 20651701521 is 12510715602.

It is not a de Polignac number, because 20651701521 - 2³ = 20651701513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20651701621) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 17756686 + ... + 17757848.

It is an arithmetic number, because the mean of its divisors is an integer number (500613120).

Almost surely, 2^20651701521 is an apocalyptic number.

It is an amenable number.

20651701521 is a deficient number, since it is larger than the sum of its proper divisors (11387538159).

20651701521 is a wasteful number, since it uses less digits than its factorization.

20651701521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1546.

The product of its (nonzero) digits is 4200, while the sum is 30.

The spelling of 20651701521 in words is "twenty billion, six hundred fifty-one million, seven hundred one thousand, five hundred twenty-one".