22780165 has 4 divisors (see below), whose sum is σ = 27336204. Its totient is φ = 18224128.

The previous prime is 22780157. The next prime is 22780169. The reversal of 22780165 is 56108722.

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 17313921 + 5466244 = 4161^2 + 2338^2 .

It is a cyclic number.

It is not a de Polignac number, because 22780165 - 2³ = 22780157 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22780169) 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, 2278012 + ... + 2278021.

It is an arithmetic number, because the mean of its divisors is an integer number (6834051).

Almost surely, 2^22780165 is an apocalyptic number.

It is an amenable number.

22780165 is a deficient number, since it is larger than the sum of its proper divisors (4556039).

22780165 is an equidigital number, since it uses as much as digits as its factorization.

22780165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4556038.

The product of its (nonzero) digits is 6720, while the sum is 31.

The square root of 22780165 is about 4772.8571107880. The cubic root of 22780165 is about 283.4777356962.

Adding to 22780165 its reverse (56108722), we get a palindrome (78888887).

The spelling of 22780165 in words is "twenty-two million, seven hundred eighty thousand, one hundred sixty-five".