22118809 has 2 divisors, whose sum is σ = 22118810. Its totient is φ = 22118808.

The previous prime is 22118807. The next prime is 22118839. The reversal of 22118809 is 90881122.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13286025 + 8832784 = 3645^2 + 2972^2 .

It is a cyclic number.

It is not a de Polignac number, because 22118809 - 2¹ = 22118807 is a prime.

Together with 22118807, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (22118807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11059404 + 11059405.

It is an arithmetic number, because the mean of its divisors is an integer number (11059405).

Almost surely, 2^22118809 is an apocalyptic number.

It is an amenable number.

22118809 is a deficient number, since it is larger than the sum of its proper divisors (1).

22118809 is an equidigital number, since it uses as much as digits as its factorization.

22118809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2304, while the sum is 31.

The square root of 22118809 is about 4703.0637886382. The cubic root of 22118809 is about 280.7074330708.

The spelling of 22118809 in words is "twenty-two million, one hundred eighteen thousand, eight hundred nine".