20663424 has 80 divisors (see below), whose sum is σ = 61524870. Its totient is φ = 6884352.

The previous prime is 20663417. The next prime is 20663437. The reversal of 20663424 is 42436602.

20663424 is a `hidden beast` number, since 2 + 0 + 6 + 634 + 24 = 666.

It can be written as a sum of positive squares in only one way, i.e., 15681600 + 4981824 = 3960^2 + 2232^2 .

It is a hoax number, since the sum of its digits (27) 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 (27).

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 9372 + ... + 11364.

Almost surely, 2^20663424 is an apocalyptic number.

20663424 is a gapful number since it is divisible by the number (24) 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 20663424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30762435).

20663424 is an abundant number, since it is smaller than the sum of its proper divisors (40861446).

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

20663424 is an equidigital number, since it uses as much as digits as its factorization.

20663424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2019 (or 1998 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 27.

The square root of 20663424 is about 4545.7039058874. The cubic root of 20663424 is about 274.4105235561.

The spelling of 20663424 in words is "twenty million, six hundred sixty-three thousand, four hundred twenty-four".