22128709 has 8 divisors (see below), whose sum is σ = 22545432. Its totient is φ = 21715200.

The previous prime is 22128683. The next prime is 22128721. The reversal of 22128709 is 90782122.

It can be written as a sum of positive squares in 4 ways, for example, as 245025 + 21883684 = 495^2 + 4678^2 .

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 22128709 - 2⁷ = 22128581 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22128739) 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, 16359 + ... + 17659.

It is an arithmetic number, because the mean of its divisors is an integer number (2818179).

Almost surely, 2^22128709 is an apocalyptic number.

It is an amenable number.

22128709 is a deficient number, since it is larger than the sum of its proper divisors (416723).

22128709 is a wasteful number, since it uses less digits than its factorization.

22128709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1607.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 22128709 is about 4704.1161762865. The cubic root of 22128709 is about 280.7493067702.

The spelling of 22128709 in words is "twenty-two million, one hundred twenty-eight thousand, seven hundred nine".