20822891 has 4 divisors (see below), whose sum is σ = 20939400. Its totient is φ = 20706384.

The previous prime is 20822887. The next prime is 20822933. The reversal of 20822891 is 19822802.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20822891 - 2² = 20822887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20822821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57986 + ... + 58343.

It is an arithmetic number, because the mean of its divisors is an integer number (5234850).

Almost surely, 2^20822891 is an apocalyptic number.

20822891 is a deficient number, since it is larger than the sum of its proper divisors (116509).

20822891 is a wasteful number, since it uses less digits than its factorization.

20822891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116508.

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 20822891 is about 4563.2106021967. The cubic root of 20822891 is about 275.1146232914.

The spelling of 20822891 in words is "twenty million, eight hundred twenty-two thousand, eight hundred ninety-one".