21279422 has 4 divisors (see below), whose sum is σ = 31919136. Its totient is φ = 10639710.

The previous prime is 21279421. The next prime is 21279431. The reversal of 21279422 is 22497212.

It is a semiprime because it is the product of two primes.

It is a congruent number.

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

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5319854 + ... + 5319857.

It is an arithmetic number, because the mean of its divisors is an integer number (7979784).

Almost surely, 2^21279422 is an apocalyptic number.

21279422 is a deficient number, since it is larger than the sum of its proper divisors (10639714).

21279422 is a wasteful number, since it uses less digits than its factorization.

21279422 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10639713.

The product of its digits is 4032, while the sum is 29.

The square root of 21279422 is about 4612.9623887476. The cubic root of 21279422 is about 277.1106874735.

The spelling of 21279422 in words is "twenty-one million, two hundred seventy-nine thousand, four hundred twenty-two".