21926966661 has 12 divisors (see below), whose sum is σ = 31679526060. Its totient is φ = 14614635840.

The previous prime is 21926966657. The next prime is 21926966669. The reversal of 21926966661 is 16666962912.

It can be written as a sum of positive squares in 2 ways, for example, as 904866561 + 21022100100 = 30081^2 + 144990^2 .

It is not a de Polignac number, because 21926966661 - 2² = 21926966657 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21926966598 and 21926966607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21926966669) 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 11 ways as a sum of consecutive naturals, for example, 236610 + ... + 315971.

It is an arithmetic number, because the mean of its divisors is an integer number (2639960505).

Almost surely, 2^21926966661 is an apocalyptic number.

It is an amenable number.

21926966661 is a deficient number, since it is larger than the sum of its proper divisors (9752559399).

21926966661 is a wasteful number, since it uses less digits than its factorization.

21926966661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 556996 (or 556993 counting only the distinct ones).

The product of its digits is 2519424, while the sum is 54.

The spelling of 21926966661 in words is "twenty-one billion, nine hundred twenty-six million, nine hundred sixty-six thousand, six hundred sixty-one".