22187989 has 2 divisors, whose sum is σ = 22187990. Its totient is φ = 22187988.

The previous prime is 22187981. The next prime is 22187993. The reversal of 22187989 is 98978122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12215025 + 9972964 = 3495^2 + 3158^2 .

It is a cyclic number.

It is not a de Polignac number, because 22187989 - 2³ = 22187981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22187981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11093994 + 11093995.

It is an arithmetic number, because the mean of its divisors is an integer number (11093995).

Almost surely, 2^22187989 is an apocalyptic number.

It is an amenable number.

22187989 is a deficient number, since it is larger than the sum of its proper divisors (1).

22187989 is an equidigital number, since it uses as much as digits as its factorization.

22187989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145152, while the sum is 46.

The square root of 22187989 is about 4710.4128269187. The cubic root of 22187989 is about 280.9997804822. Note that the first 3 decimals are identical.

The spelling of 22187989 in words is "twenty-two million, one hundred eighty-seven thousand, nine hundred eighty-nine".