21279424 has 28 divisors (see below), whose sum is σ = 42437304. Its totient is φ = 10586624.

The previous prime is 21279421. The next prime is 21279431. The reversal of 21279424 is 42497212.

It is not an unprimeable number, because it can be changed into a prime (21279421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14199 + ... + 15625.

It is an arithmetic number, because the mean of its divisors is an integer number (1515618).

Almost surely, 2^21279424 is an apocalyptic number.

It is an amenable number.

21279424 is a deficient number, since it is larger than the sum of its proper divisors (21157880).

21279424 is a wasteful number, since it uses less digits than its factorization.

21279424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1672 (or 1662 counting only the distinct ones).

The product of its digits is 8064, while the sum is 31.

The square root of 21279424 is about 4612.9626055280. The cubic root of 21279424 is about 277.1106961552.

The spelling of 21279424 in words is "twenty-one million, two hundred seventy-nine thousand, four hundred twenty-four".