20811844 has 9 divisors (see below), whose sum is σ = 36436701. Its totient is φ = 10401360.

The previous prime is 20811827. The next prime is 20811853. The reversal of 20811844 is 44811802.

The square root of 20811844 is 4562.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 12517444 + 8294400 = 3538^2 + 2880^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 7984 + ... + 10264.

Almost surely, 2^20811844 is an apocalyptic number.

20811844 is the 4562-nd square number.

It is an amenable number.

20811844 is a deficient number, since it is larger than the sum of its proper divisors (15624857).

20811844 is an frugal number, since it uses more digits than its factorization.

20811844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4566 (or 2283 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 28.

The cubic root of 20811844 is about 275.0659632397.

The spelling of 20811844 in words is "twenty million, eight hundred eleven thousand, eight hundred forty-four".