22155881 has 16 divisors (see below), whose sum is σ = 25608960. Its totient is φ = 18956880.

The previous prime is 22155869. The next prime is 22155893. The reversal of 22155881 is 18855122.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (22155869) and next prime (22155893).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-22155881 is a prime.

It is a super-2 number, since 2×22155881² = 981766125772322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (22155841) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47210 + ... + 47676.

It is an arithmetic number, because the mean of its divisors is an integer number (1600560).

Almost surely, 2^22155881 is an apocalyptic number.

It is an amenable number.

22155881 is a deficient number, since it is larger than the sum of its proper divisors (3453079).

22155881 is a wasteful number, since it uses less digits than its factorization.

22155881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 724.

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

The square root of 22155881 is about 4707.0033991915. The cubic root of 22155881 is about 280.8641711292.

Subtracting from 22155881 its sum of digits (32), we obtain a square (22155849 = 4707²).

The spelling of 22155881 in words is "twenty-two million, one hundred fifty-five thousand, eight hundred eighty-one".