20222891 has 4 divisors (see below), whose sum is σ = 21778512. Its totient is φ = 18667272.

The previous prime is 20222887. The next prime is 20222933. The reversal of 20222891 is 19822202.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19822202 = 2 ⋅9911101.

It is not a de Polignac number, because 20222891 - 2² = 20222887 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20222891.

It is not an unprimeable number, because it can be changed into a prime (20222861) by changing a digit.

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, 777791 + ... + 777816.

It is an arithmetic number, because the mean of its divisors is an integer number (5444628).

Almost surely, 2^20222891 is an apocalyptic number.

20222891 is a deficient number, since it is larger than the sum of its proper divisors (1555621).

20222891 is a wasteful number, since it uses less digits than its factorization.

20222891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1555620.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 20222891 is about 4496.9868801232. The cubic root of 20222891 is about 272.4464041832.

Subtracting from 20222891 its reverse (19822202), we obtain a square (400689 = 633²).

It can be divided in two parts, 2022 and 2891, that added together give a cube (4913 = 17³).

The spelling of 20222891 in words is "twenty million, two hundred twenty-two thousand, eight hundred ninety-one".