221219989 has 2 divisors, whose sum is σ = 221219990. Its totient is φ = 221219988.

The previous prime is 221219941. The next prime is 221220007. The reversal of 221219989 is 989912122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 202123089 + 19096900 = 14217^2 + 4370^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221219989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221211989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110609994 + 110609995.

It is an arithmetic number, because the mean of its divisors is an integer number (110609995).

Almost surely, 2^221219989 is an apocalyptic number.

It is an amenable number.

221219989 is a deficient number, since it is larger than the sum of its proper divisors (1).

221219989 is an equidigital number, since it uses as much as digits as its factorization.

221219989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 46656, while the sum is 43.

The square root of 221219989 is about 14873.4659377026. The cubic root of 221219989 is about 604.7949025893.

It can be divided in two parts, 2212 and 19989, that added together give a square (22201 = 149²).

The spelling of 221219989 in words is "two hundred twenty-one million, two hundred nineteen thousand, nine hundred eighty-nine".