21920568200091 has 24 divisors (see below), whose sum is σ = 34541723034624. Its totient is φ = 13285107606960.

The previous prime is 21920568200087. The next prime is 21920568200093. The reversal of 21920568200091 is 19000286502912.

It is a happy number.

It is not a de Polignac number, because 21920568200091 - 2² = 21920568200087 is a prime.

It is a super-2 number, since 2×21920568200091² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21920568200093) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17021250 + ... + 18263736.

It is an arithmetic number, because the mean of its divisors is an integer number (1439238459776).

Almost surely, 2^{21920568200091} is an apocalyptic number.

21920568200091 is a deficient number, since it is larger than the sum of its proper divisors (12621154834533).

21920568200091 is a wasteful number, since it uses less digits than its factorization.

21920568200091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1420711 (or 1420708 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 45.

The spelling of 21920568200091 in words is "twenty-one trillion, nine hundred twenty billion, five hundred sixty-eight million, two hundred thousand, ninety-one".