21852189 has 6 divisors (see below), whose sum is σ = 31564286. Its totient is φ = 14568120.

The previous prime is 21852169. The next prime is 21852197. The reversal of 21852189 is 98125812.

It can be written as a sum of positive squares in only one way, i.e., 17264025 + 4588164 = 4155^2 + 2142^2 .

It is a de Polignac number, because none of the positive numbers 2^k-21852189 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21852169) 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, 1214002 + ... + 1214019.

Almost surely, 2^21852189 is an apocalyptic number.

It is an amenable number.

21852189 is a deficient number, since it is larger than the sum of its proper divisors (9712097).

21852189 is a wasteful number, since it uses less digits than its factorization.

21852189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2428027 (or 2428024 counting only the distinct ones).

The product of its digits is 11520, while the sum is 36.

The square root of 21852189 is about 4674.6324989244. The cubic root of 21852189 is about 279.5749887062.

The spelling of 21852189 in words is "twenty-one million, eight hundred fifty-two thousand, one hundred eighty-nine".