20845808 has 40 divisors (see below), whose sum is σ = 43108848. Its totient is φ = 9731072.

The previous prime is 20845771. The next prime is 20845823. The reversal of 20845808 is 80854802.

It is a super-2 number, since 2×20845808² = 869095422345728, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46835 + ... + 47277.

Almost surely, 2^20845808 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 20845808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21554424).

20845808 is an abundant number, since it is smaller than the sum of its proper divisors (22263040).

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

20845808 is a wasteful number, since it uses less digits than its factorization.

20845808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 641 (or 635 counting only the distinct ones).

The product of its (nonzero) digits is 20480, while the sum is 35.

The square root of 20845808 is about 4565.7209726395. The cubic root of 20845808 is about 275.2155137054.

The spelling of 20845808 in words is "twenty million, eight hundred forty-five thousand, eight hundred eight".