22145661 has 6 divisors (see below), whose sum is σ = 31988190. Its totient is φ = 14763768.

The previous prime is 22145657. The next prime is 22145663. The reversal of 22145661 is 16654122.

It can be written as a sum of positive squares in only one way, i.e., 17388900 + 4756761 = 4170^2 + 2181^2 .

It is not a de Polignac number, because 22145661 - 2² = 22145657 is a prime.

It is a super-2 number, since 2×22145661² = 980860602253842, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22145663) 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, 1230306 + ... + 1230323.

It is an arithmetic number, because the mean of its divisors is an integer number (5331365).

Almost surely, 2^22145661 is an apocalyptic number.

It is an amenable number.

22145661 is a deficient number, since it is larger than the sum of its proper divisors (9842529).

22145661 is a wasteful number, since it uses less digits than its factorization.

22145661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2460635 (or 2460632 counting only the distinct ones).

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

The square root of 22145661 is about 4705.9176575882. The cubic root of 22145661 is about 280.8209790861.

Adding to 22145661 its reverse (16654122), we get a palindrome (38799783).

It can be divided in two parts, 2214 and 5661, that added together give a triangular number (7875 = T₁₂₅).

The spelling of 22145661 in words is "twenty-two million, one hundred forty-five thousand, six hundred sixty-one".