22161564 has 18 divisors (see below), whose sum is σ = 56019600. Its totient is φ = 7387176.

The previous prime is 22161563. The next prime is 22161571. The reversal of 22161564 is 46516122.

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×22161564² = 982269837852192, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22161563) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 307764 + ... + 307835.

It is an arithmetic number, because the mean of its divisors is an integer number (3112200).

Almost surely, 2^22161564 is an apocalyptic number.

It is an amenable number.

22161564 is an abundant number, since it is smaller than the sum of its proper divisors (33858036).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

22161564 is a wasteful number, since it uses less digits than its factorization.

22161564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 615609 (or 615604 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 22161564 is about 4707.6070354268. The cubic root of 22161564 is about 280.8881830327. Note that the first 3 decimals are identical.

Adding to 22161564 its reverse (46516122), we get a palindrome (68677686).

The spelling of 22161564 in words is "twenty-two million, one hundred sixty-one thousand, five hundred sixty-four".