20663808 has 80 divisors (see below), whose sum is σ = 60103296. Its totient is φ = 6256640.

The previous prime is 20663807. The next prime is 20663831. The reversal of 20663808 is 80836602.

It is a super-2 number, since 2×20663808² = 853985922121728, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20663801) 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, 16285 + ... + 17507.

Almost surely, 2^20663808 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20663808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30051648).

20663808 is an abundant number, since it is smaller than the sum of its proper divisors (39439488).

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

20663808 is a wasteful number, since it uses less digits than its factorization.

20663808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1255 (or 1239 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 20663808 is about 4545.7461433740. The cubic root of 20663808 is about 274.4122233871.

The spelling of 20663808 in words is "twenty million, six hundred sixty-three thousand, eight hundred eight".