22818181 has 8 divisors (see below), whose sum is σ = 23517144. Its totient is φ = 22126080.

The previous prime is 22818179. The next prime is 22818227. The reversal of 22818181 is 18181822.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 6937956 + 15880225 = 2634^2 + 3985^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 22818181 - 2¹ = 22818179 is a prime.

It is a super-2 number, since 2×22818181² = 1041338768297522, 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 (22818151) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5485 + ... + 8701.

It is an arithmetic number, because the mean of its divisors is an integer number (2939643).

Almost surely, 2^22818181 is an apocalyptic number.

It is an amenable number.

22818181 is a deficient number, since it is larger than the sum of its proper divisors (698963).

22818181 is a wasteful number, since it uses less digits than its factorization.

22818181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3431.

The product of its digits is 2048, while the sum is 31.

The square root of 22818181 is about 4776.8379708757. The cubic root of 22818181 is about 283.6353391839.

The spelling of 22818181 in words is "twenty-two million, eight hundred eighteen thousand, one hundred eighty-one".