21279250 has 32 divisors (see below), whose sum is σ = 40704768. Its totient is φ = 8326000.

The previous prime is 21279241. The next prime is 21279253. The reversal of 21279250 is 5297212.

It is not an unprimeable number, because it can be changed into a prime (21279253) 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, 10845 + ... + 12655.

It is an arithmetic number, because the mean of its divisors is an integer number (1272024).

Almost surely, 2^21279250 is an apocalyptic number.

21279250 is a deficient number, since it is larger than the sum of its proper divisors (19425518).

21279250 is a wasteful number, since it uses less digits than its factorization.

21279250 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1875 (or 1865 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 21279250 is about 4612.9437455924. The cubic root of 21279250 is about 277.1099408498.

The spelling of 21279250 in words is "twenty-one million, two hundred seventy-nine thousand, two hundred fifty".