20440864 has 24 divisors (see below), whose sum is σ = 41102208. Its totient is φ = 10002240.

The previous prime is 20440801. The next prime is 20440877. The reversal of 20440864 is 46804402.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5292 + ... + 8299.

It is an arithmetic number, because the mean of its divisors is an integer number (1712592).

Almost surely, 2^20440864 is an apocalyptic number.

It is an amenable number.

20440864 is an abundant number, since it is smaller than the sum of its proper divisors (20661344).

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

20440864 is a wasteful number, since it uses less digits than its factorization.

20440864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13648 (or 13640 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 28.

The square root of 20440864 is about 4521.1573739475. The cubic root of 20440864 is about 273.4217652921.

The spelling of 20440864 in words is "twenty million, four hundred forty thousand, eight hundred sixty-four".