20686680 has 96 divisors (see below), whose sum is σ = 76845600. Its totient is φ = 4727808.

The previous prime is 20686661. The next prime is 20686681. The reversal of 20686680 is 8668602.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20686681) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1585 + ... + 6624.

It is an arithmetic number, because the mean of its divisors is an integer number (800475).

Almost surely, 2^20686680 is an apocalyptic number.

20686680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20686680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38422800).

20686680 is an abundant number, since it is smaller than the sum of its proper divisors (56158920).

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

20686680 is a wasteful number, since it uses less digits than its factorization.

20686680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8233 (or 8226 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 20686680 is about 4548.2612062194. The cubic root of 20686680 is about 274.5134316141.

The spelling of 20686680 in words is "twenty million, six hundred eighty-six thousand, six hundred eighty".