22011865 has 4 divisors (see below), whose sum is σ = 26414244. Its totient is φ = 17609488.

The previous prime is 22011863. The next prime is 22011877. The reversal of 22011865 is 56811022.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56811022 = 2 ⋅28405511.

It can be written as a sum of positive squares in 2 ways, for example, as 11943936 + 10067929 = 3456^2 + 3173^2 .

It is a cyclic number.

It is not a de Polignac number, because 22011865 - 2¹ = 22011863 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (22011863) 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, 2201182 + ... + 2201191.

It is an arithmetic number, because the mean of its divisors is an integer number (6603561).

Almost surely, 2^22011865 is an apocalyptic number.

It is an amenable number.

22011865 is a deficient number, since it is larger than the sum of its proper divisors (4402379).

22011865 is an equidigital number, since it uses as much as digits as its factorization.

22011865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4402378.

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 22011865 is about 4691.6804025850. The cubic root of 22011865 is about 280.2542970378.

Adding to 22011865 its reverse (56811022), we get a palindrome (78822887).

The spelling of 22011865 in words is "twenty-two million, eleven thousand, eight hundred sixty-five".