20999791922 has 18 divisors (see below), whose sum is σ = 32262813567. Its totient is φ = 10251408636.

The previous prime is 20999791889. The next prime is 20999791937. The reversal of 20999791922 is 22919799902.

It can be written as a sum of positive squares in only one way, i.e., 10499895961 + 10499895961 = 102469^2 + 102469^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=102469.

It is a Duffinian number.

It is an unprimeable number.

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 8 ways as a sum of consecutive naturals, for example, 8811143 + ... + 8813525.

Almost surely, 2^20999791922 is an apocalyptic number.

20999791922 is a deficient number, since it is larger than the sum of its proper divisors (11263021645).

20999791922 is an frugal number, since it uses more digits than its factorization.

20999791922 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4854 (or 2428 counting only the distinct ones).

The product of its (nonzero) digits is 3306744, while the sum is 59.

The spelling of 20999791922 in words is "twenty billion, nine hundred ninety-nine million, seven hundred ninety-one thousand, nine hundred twenty-two".