21943225 has 12 divisors (see below), whose sum is σ = 27657580. Its totient is φ = 17265600.

The previous prime is 21943213. The next prime is 21943231. The reversal of 21943225 is 52234912.

It can be written as a sum of positive squares in 6 ways, for example, as 6110784 + 15832441 = 2472^2 + 3979^2 .

It is not a de Polignac number, because 21943225 - 2⁵ = 21943193 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21943193 and 21943202.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5670 + ... + 8719.

Almost surely, 2^21943225 is an apocalyptic number.

21943225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21943225 is a deficient number, since it is larger than the sum of its proper divisors (5714355).

21943225 is a wasteful number, since it uses less digits than its factorization.

21943225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14460 (or 14455 counting only the distinct ones).

The product of its digits is 4320, while the sum is 28.

The square root of 21943225 is about 4684.3596147179. The cubic root of 21943225 is about 279.9626863542.

The spelling of 21943225 in words is "twenty-one million, nine hundred forty-three thousand, two hundred twenty-five".