220919891 has 4 divisors (see below), whose sum is σ = 221020800. Its totient is φ = 220818984.

The previous prime is 220919887. The next prime is 220919903. The reversal of 220919891 is 198919022.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 198919022 = 2 ⋅99459511.

It is a cyclic number.

It is not a de Polignac number, because 220919891 - 2² = 220919887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (220919801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47096 + ... + 51573.

It is an arithmetic number, because the mean of its divisors is an integer number (55255200).

Almost surely, 2^220919891 is an apocalyptic number.

220919891 is a deficient number, since it is larger than the sum of its proper divisors (100909).

220919891 is an equidigital number, since it uses as much as digits as its factorization.

220919891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100908.

The product of its (nonzero) digits is 23328, while the sum is 41.

The square root of 220919891 is about 14863.3741458661. The cubic root of 220919891 is about 604.5212988126.

The spelling of 220919891 in words is "two hundred twenty million, nine hundred nineteen thousand, eight hundred ninety-one".