22139221 has 16 divisors (see below), whose sum is σ = 24801840. Its totient is φ = 19630080.

The previous prime is 22139203. The next prime is 22139231. The reversal of 22139221 is 12293122.

It can be written as a sum of positive squares in 8 ways, for example, as 7623121 + 14516100 = 2761^2 + 3810^2 .

It is a 6-Lehmer number, since φ(22139221) divides (22139221-1)⁶.

It is a cyclic number.

It is not a de Polignac number, because 22139221 - 2¹¹ = 22137173 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 22139192 and 22139201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22139231) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38625 + ... + 39193.

It is an arithmetic number, because the mean of its divisors is an integer number (1550115).

Almost surely, 2^22139221 is an apocalyptic number.

It is an amenable number.

22139221 is a deficient number, since it is larger than the sum of its proper divisors (2662619).

22139221 is a wasteful number, since it uses less digits than its factorization.

22139221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 696.

The product of its digits is 432, while the sum is 22.

The square root of 22139221 is about 4705.2333629694. The cubic root of 22139221 is about 280.7937553569.

The spelling of 22139221 in words is "twenty-two million, one hundred thirty-nine thousand, two hundred twenty-one".