221499989 has 2 divisors, whose sum is σ = 221499990. Its totient is φ = 221499988.

The previous prime is 221499979. The next prime is 221500039. The reversal of 221499989 is 989994122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 212197489 + 9302500 = 14567^2 + 3050^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221499989 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 221499989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221499979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110749994 + 110749995.

It is an arithmetic number, because the mean of its divisors is an integer number (110749995).

Almost surely, 2^221499989 is an apocalyptic number.

It is an amenable number.

221499989 is a deficient number, since it is larger than the sum of its proper divisors (1).

221499989 is an equidigital number, since it uses as much as digits as its factorization.

221499989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 839808, while the sum is 53.

The square root of 221499989 is about 14882.8756965850. The cubic root of 221499989 is about 605.0499596746.

The spelling of 221499989 in words is "two hundred twenty-one million, four hundred ninety-nine thousand, nine hundred eighty-nine".