22728861 has 6 divisors (see below), whose sum is σ = 32830590. Its totient is φ = 15152568.

The previous prime is 22728857. The next prime is 22728869. The reversal of 22728861 is 16882722.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 11799225 + 10929636 = 3435^2 + 3306^2 .

It is not a de Polignac number, because 22728861 - 2² = 22728857 is a prime.

It is a super-2 number, since 2×22728861² = 1033202244714642, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22728869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1262706 + ... + 1262723.

It is an arithmetic number, because the mean of its divisors is an integer number (5471765).

Almost surely, 2^22728861 is an apocalyptic number.

It is an amenable number.

22728861 is a deficient number, since it is larger than the sum of its proper divisors (10101729).

22728861 is a wasteful number, since it uses less digits than its factorization.

22728861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2525435 (or 2525432 counting only the distinct ones).

The product of its digits is 21504, while the sum is 36.

The square root of 22728861 is about 4767.4795227667. The cubic root of 22728861 is about 283.2647657222.

The spelling of 22728861 in words is "twenty-two million, seven hundred twenty-eight thousand, eight hundred sixty-one".