2172227891 has 2 divisors, whose sum is σ = 2172227892. Its totient is φ = 2172227890.

The previous prime is 2172227881. The next prime is 2172227917. The reversal of 2172227891 is 1987222712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2172227891 - 2¹⁴ = 2172211507 is a prime.

It is not a weakly prime, because it can be changed into another prime (2172227821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1086113945 + 1086113946.

It is an arithmetic number, because the mean of its divisors is an integer number (1086113946).

Almost surely, 2^2172227891 is an apocalyptic number.

2172227891 is a deficient number, since it is larger than the sum of its proper divisors (1).

2172227891 is an equidigital number, since it uses as much as digits as its factorization.

2172227891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 56448, while the sum is 41.

The square root of 2172227891 is about 46607.1656615160. The cubic root of 2172227891 is about 1295.0955025646.

The spelling of 2172227891 in words is "two billion, one hundred seventy-two million, two hundred twenty-seven thousand, eight hundred ninety-one".