20989100051 has 4 divisors (see below), whose sum is σ = 20995701504. Its totient is φ = 20982498600.

The previous prime is 20989099979. The next prime is 20989100053. The reversal of 20989100051 is 15000198902.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20989100051 - 2³⁰ = 19915358227 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20989099984 and 20989100020.

It is not an unprimeable number, because it can be changed into a prime (20989100053) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3295955 + ... + 3302316.

It is an arithmetic number, because the mean of its divisors is an integer number (5248925376).

Almost surely, 2^20989100051 is an apocalyptic number.

20989100051 is a deficient number, since it is larger than the sum of its proper divisors (6601453).

20989100051 is an equidigital number, since it uses as much as digits as its factorization.

20989100051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6601452.

The product of its (nonzero) digits is 6480, while the sum is 35.

Adding to 20989100051 its reverse (15000198902), we get a palindrome (35989298953).

The spelling of 20989100051 in words is "twenty billion, nine hundred eighty-nine million, one hundred thousand, fifty-one".