20668920 has 64 divisors (see below), whose sum is σ = 63534240. Its totient is φ = 5376000.

The previous prime is 20668919. The next prime is 20668931. The reversal of 20668920 is 2986602.

It is a congruent number.

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, 2820 + ... + 7020.

Almost surely, 2^20668920 is an apocalyptic number.

20668920 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 20668920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31767120).

20668920 is an abundant number, since it is smaller than the sum of its proper divisors (42865320).

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

20668920 is a wasteful number, since it uses less digits than its factorization.

20668920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4256 (or 4252 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 20668920 is about 4546.3083925312. The cubic root of 20668920 is about 274.4348503818.

The spelling of 20668920 in words is "twenty million, six hundred sixty-eight thousand, nine hundred twenty".