221995889 has 2 divisors, whose sum is σ = 221995890. Its totient is φ = 221995888.

The previous prime is 221995859. The next prime is 221995909. The reversal of 221995889 is 988599122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 148035889 + 73960000 = 12167^2 + 8600^2 .

It is a cyclic number.

It is not a de Polignac number, because 221995889 - 2⁸ = 221995633 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221995889.

It is not a weakly prime, because it can be changed into another prime (221995859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110997944 + 110997945.

It is an arithmetic number, because the mean of its divisors is an integer number (110997945).

Almost surely, 2^221995889 is an apocalyptic number.

It is an amenable number.

221995889 is a deficient number, since it is larger than the sum of its proper divisors (1).

221995889 is an equidigital number, since it uses as much as digits as its factorization.

221995889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 933120, while the sum is 53.

The square root of 221995889 is about 14899.5264689855. The cubic root of 221995889 is about 605.5011570445.

The spelling of 221995889 in words is "two hundred twenty-one million, nine hundred ninety-five thousand, eight hundred eighty-nine".