20951972089 has 4 divisors (see below), whose sum is σ = 21307090320. Its totient is φ = 20596853860.

The previous prime is 20951972057. The next prime is 20951972143. The reversal of 20951972089 is 98027915902.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20951972089 - 2⁵ = 20951972057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20951972039) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 177559027 + ... + 177559144.

It is an arithmetic number, because the mean of its divisors is an integer number (5326772580).

Almost surely, 2^20951972089 is an apocalyptic number.

It is an amenable number.

20951972089 is a deficient number, since it is larger than the sum of its proper divisors (355118231).

20951972089 is an equidigital number, since it uses as much as digits as its factorization.

20951972089 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 355118230.

The product of its (nonzero) digits is 816480, while the sum is 52.

The spelling of 20951972089 in words is "twenty billion, nine hundred fifty-one million, nine hundred seventy-two thousand, eighty-nine".