20686668 has 24 divisors (see below), whose sum is σ = 50809920. Its totient is φ = 6532560.

The previous prime is 20686661. The next prime is 20686681. The reversal of 20686668 is 86668602.

It is not an unprimeable number, because it can be changed into a prime (20686661) 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, 45138 + ... + 45593.

It is an arithmetic number, because the mean of its divisors is an integer number (2117080).

Almost surely, 2^20686668 is an apocalyptic number.

It is an amenable number.

20686668 is an abundant number, since it is smaller than the sum of its proper divisors (30123252).

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

20686668 is a wasteful number, since it uses less digits than its factorization.

20686668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90757 (or 90755 counting only the distinct ones).

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

The square root of 20686668 is about 4548.2598870337. The cubic root of 20686668 is about 274.5133785338.

The spelling of 20686668 in words is "twenty million, six hundred eighty-six thousand, six hundred sixty-eight".