20666690 has 32 divisors (see below), whose sum is σ = 41057280. Its totient is φ = 7427200.

The previous prime is 20666689. The next prime is 20666743. The reversal of 20666690 is 9666602.

It is a super-2 number, since 2×20666690² = 854224151112200, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20666690.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8735 + ... + 10845.

It is an arithmetic number, because the mean of its divisors is an integer number (1283040).

Almost surely, 2^20666690 is an apocalyptic number.

20666690 is a deficient number, since it is larger than the sum of its proper divisors (20390590).

20666690 is a wasteful number, since it uses less digits than its factorization.

20666690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2218.

The product of its (nonzero) digits is 23328, while the sum is 35.

The square root of 20666690 is about 4546.0631319857. The cubic root of 20666690 is about 274.4249803011.

The spelling of 20666690 in words is "twenty million, six hundred sixty-six thousand, six hundred ninety".