22161665 has 8 divisors (see below), whose sum is σ = 26661480. Its totient is φ = 17684352.

The previous prime is 22161661. The next prime is 22161679. The reversal of 22161665 is 56616122.

It can be written as a sum of positive squares in 4 ways, for example, as 3568321 + 18593344 = 1889^2 + 4312^2 .

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 22161665 - 2² = 22161661 is a prime.

It is a super-2 number, since 2×22161665² = 982278791144450, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (22161661) 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, 3374 + ... + 7463.

It is an arithmetic number, because the mean of its divisors is an integer number (3332685).

Almost surely, 2^22161665 is an apocalyptic number.

It is an amenable number.

22161665 is a deficient number, since it is larger than the sum of its proper divisors (4499815).

22161665 is a wasteful number, since it uses less digits than its factorization.

22161665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11251.

The product of its digits is 4320, while the sum is 29.

The square root of 22161665 is about 4707.6177627331. The cubic root of 22161665 is about 280.8886097424. Note that the first 3 decimals are identical.

Adding to 22161665 its reverse (56616122), we get a palindrome (78777787).

The spelling of 22161665 in words is "twenty-two million, one hundred sixty-one thousand, six hundred sixty-five".