22521661 has 8 divisors (see below), whose sum is σ = 23739480. Its totient is φ = 21333312.

The previous prime is 22521647. The next prime is 22521673. The reversal of 22521661 is 16612522.

It can be written as a sum of positive squares in 4 ways, for example, as 9060100 + 13461561 = 3010^2 + 3669^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 22521661 - 2⁷ = 22521533 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22521461) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5790 + ... + 8863.

It is an arithmetic number, because the mean of its divisors is an integer number (2967435).

Almost surely, 2^22521661 is an apocalyptic number.

It is an amenable number.

22521661 is a deficient number, since it is larger than the sum of its proper divisors (1217819).

22521661 is a wasteful number, since it uses less digits than its factorization.

22521661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14735.

The product of its digits is 1440, while the sum is 25.

The square root of 22521661 is about 4745.6992108645. The cubic root of 22521661 is about 282.4013741918.

The spelling of 22521661 in words is "twenty-two million, five hundred twenty-one thousand, six hundred sixty-one".