22778881 has 4 divisors (see below), whose sum is σ = 22844500. Its totient is φ = 22713264.

The previous prime is 22778869. The next prime is 22778911. The reversal of 22778881 is 18887722.

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 10112400 + 12666481 = 3180^2 + 3559^2 .

It is a cyclic number.

It is not a de Polignac number, because 22778881 - 2⁵ = 22778849 is a prime.

It is a super-2 number, since 2×22778881² = 1037754839224322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (22778081) 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, 32286 + ... + 32983.

It is an arithmetic number, because the mean of its divisors is an integer number (5711125).

Almost surely, 2^22778881 is an apocalyptic number.

It is an amenable number.

22778881 is a deficient number, since it is larger than the sum of its proper divisors (65619).

22778881 is an equidigital number, since it uses as much as digits as its factorization.

22778881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65618.

The product of its digits is 100352, while the sum is 43.

The square root of 22778881 is about 4772.7225982661. The cubic root of 22778881 is about 283.4724095385.

The spelling of 22778881 in words is "twenty-two million, seven hundred seventy-eight thousand, eight hundred eighty-one".