21969754561 has 16 divisors (see below), whose sum is σ = 22429440000. Its totient is φ = 21515257296.

The previous prime is 21969754553. The next prime is 21969754579. The reversal of 21969754561 is 16545796912.

It is a cyclic number.

It is not a de Polignac number, because 21969754561 - 2³ = 21969754553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21969752561) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6206130 + ... + 6209668.

It is an arithmetic number, because the mean of its divisors is an integer number (1401840000).

Almost surely, 2^21969754561 is an apocalyptic number.

It is an amenable number.

21969754561 is a deficient number, since it is larger than the sum of its proper divisors (459685439).

21969754561 is a wasteful number, since it uses less digits than its factorization.

21969754561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4236.

The product of its digits is 4082400, while the sum is 55.

The spelling of 21969754561 in words is "twenty-one billion, nine hundred sixty-nine million, seven hundred fifty-four thousand, five hundred sixty-one".