20645888 has 48 divisors (see below), whose sum is σ = 43783740. Its totient is φ = 9699328.

The previous prime is 20645879. The next prime is 20645899. The reversal of 20645888 is 88854602.

It can be written as a sum of positive squares in 2 ways, for example, as 19784704 + 861184 = 4448^2 + 928^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34520 + ... + 35112.

Almost surely, 2^20645888 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 20645888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21891870).

20645888 is an abundant number, since it is smaller than the sum of its proper divisors (23137852).

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

20645888 is an equidigital number, since it uses as much as digits as its factorization.

20645888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 632 (or 612 counting only the distinct ones).

The product of its (nonzero) digits is 122880, while the sum is 41.

The square root of 20645888 is about 4543.7746422991. The cubic root of 20645888 is about 274.3328754884.

The spelling of 20645888 in words is "twenty million, six hundred forty-five thousand, eight hundred eighty-eight".