22155818 has 4 divisors (see below), whose sum is σ = 33233730. Its totient is φ = 11077908.

The previous prime is 22155779. The next prime is 22155823. The reversal of 22155818 is 81855122.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81855122 = 2 ⋅40927561.

It can be written as a sum of positive squares in only one way, i.e., 13786369 + 8369449 = 3713^2 + 2893^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5538953 + ... + 5538956.

Almost surely, 2^22155818 is an apocalyptic number.

22155818 is a deficient number, since it is larger than the sum of its proper divisors (11077912).

22155818 is a wasteful number, since it uses less digits than its factorization.

22155818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11077911.

The product of its digits is 6400, while the sum is 32.

The square root of 22155818 is about 4706.9967070309. The cubic root of 22155818 is about 280.8639049175.

The spelling of 22155818 in words is "twenty-two million, one hundred fifty-five thousand, eight hundred eighteen".