21662606 has 12 divisors (see below), whose sum is σ = 37799208. Its totient is φ = 9283932.

The previous prime is 21662591. The next prime is 21662609. The reversal of 21662606 is 60626612.

It is a super-2 number, since 2×21662606² = 938536997422472, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21662609) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 110426 + ... + 110621.

It is an arithmetic number, because the mean of its divisors is an integer number (3149934).

Almost surely, 2^21662606 is an apocalyptic number.

21662606 is a deficient number, since it is larger than the sum of its proper divisors (16136602).

21662606 is a wasteful number, since it uses less digits than its factorization.

21662606 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221063 (or 221056 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 21662606 is about 4654.3104752476. The cubic root of 21662606 is about 278.7641365068.

The spelling of 21662606 in words is "twenty-one million, six hundred sixty-two thousand, six hundred six".