20668866 has 16 divisors (see below), whose sum is σ = 42455424. Its totient is φ = 6703344.

The previous prime is 20668859. The next prime is 20668867. The reversal of 20668866 is 66886602.

It is not an unprimeable number, because it can be changed into a prime (20668867) 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, 46330 + ... + 46773.

It is an arithmetic number, because the mean of its divisors is an integer number (2653464).

Almost surely, 2^20668866 is an apocalyptic number.

20668866 is an abundant number, since it is smaller than the sum of its proper divisors (21786558).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20668866 is a wasteful number, since it uses less digits than its factorization.

20668866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93145.

The product of its (nonzero) digits is 165888, while the sum is 42.

The square root of 20668866 is about 4546.3024536430. The cubic root of 20668866 is about 274.4346113838.

The spelling of 20668866 in words is "twenty million, six hundred sixty-eight thousand, eight hundred sixty-six".