22918381 has 4 divisors (see below), whose sum is σ = 23708700. Its totient is φ = 22128064.

The previous prime is 22918369. The next prime is 22918403. The reversal of 22918381 is 18381922.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3865156 + 19053225 = 1966^2 + 4365^2 .

It is a cyclic number.

It is not a de Polignac number, because 22918381 - 2⁵ = 22918349 is a prime.

It is a super-2 number, since 2×22918381² = 1050504375322322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22918361) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 395116 + ... + 395173.

It is an arithmetic number, because the mean of its divisors is an integer number (5927175).

Almost surely, 2^22918381 is an apocalyptic number.

It is an amenable number.

22918381 is a deficient number, since it is larger than the sum of its proper divisors (790319).

22918381 is an equidigital number, since it uses as much as digits as its factorization.

22918381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 790318.

The product of its digits is 6912, while the sum is 34.

The square root of 22918381 is about 4787.3145917101. The cubic root of 22918381 is about 284.0499027894.

The spelling of 22918381 in words is "twenty-two million, nine hundred eighteen thousand, three hundred eighty-one".