20949816897 has 12 divisors (see below), whose sum is σ = 30333073680. Its totient is φ = 13933209048.

The previous prime is 20949816847. The next prime is 20949816911. The reversal of 20949816897 is 79861894902.

It is not a de Polignac number, because 20949816897 - 2²³ = 20941428289 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20949816847) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2773983 + ... + 2781524.

It is an arithmetic number, because the mean of its divisors is an integer number (2527756140).

Almost surely, 2^20949816897 is an apocalyptic number.

It is an amenable number.

20949816897 is a deficient number, since it is larger than the sum of its proper divisors (9383256783).

20949816897 is a wasteful number, since it uses less digits than its factorization.

20949816897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5555932 (or 5555929 counting only the distinct ones).

The product of its (nonzero) digits is 15676416, while the sum is 63.

The spelling of 20949816897 in words is "twenty billion, nine hundred forty-nine million, eight hundred sixteen thousand, eight hundred ninety-seven".