21945250 has 32 divisors (see below), whose sum is σ = 42103152. Its totient is φ = 8560000.

The previous prime is 21945239. The next prime is 21945263. The reversal of 21945250 is 5254912.

It can be written as a sum of positive squares in 8 ways, for example, as 720801 + 21224449 = 849^2 + 4607^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9180 + ... + 11320.

Almost surely, 2^21945250 is an apocalyptic number.

21945250 is a deficient number, since it is larger than the sum of its proper divisors (20157902).

21945250 is a wasteful number, since it uses less digits than its factorization.

21945250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2199 (or 2189 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 21945250 is about 4684.5757545374. The cubic root of 21945250 is about 279.9712980784.

The spelling of 21945250 in words is "twenty-one million, nine hundred forty-five thousand, two hundred fifty".