22101666521 has 12 divisors (see below), whose sum is σ = 24470910996. Its totient is φ = 19945749120.

The previous prime is 22101666491. The next prime is 22101666553. The reversal of 22101666521 is 12566610122.

It can be written as a sum of positive squares in 2 ways, for example, as 5752464025 + 16349202496 = 75845^2 + 127864^2 .

It is not a de Polignac number, because 22101666521 - 2¹⁰ = 22101665497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (22101668521) 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, 650060 + ... + 683213.

It is an arithmetic number, because the mean of its divisors is an integer number (2039242583).

Almost surely, 2^22101666521 is an apocalyptic number.

It is an amenable number.

22101666521 is a deficient number, since it is larger than the sum of its proper divisors (2369244475).

22101666521 is a wasteful number, since it uses less digits than its factorization.

22101666521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1333432 (or 1333421 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 32.

The spelling of 22101666521 in words is "twenty-two billion, one hundred one million, six hundred sixty-six thousand, five hundred twenty-one".