21279454 has 16 divisors (see below), whose sum is σ = 37656576. Its totient is φ = 8825400.

The previous prime is 21279443. The next prime is 21279463. The reversal of 21279454 is 45497212.

It is a congruent number.

It is an unprimeable number.

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 in 7 ways as a sum of consecutive naturals, for example, 24082 + ... + 24949.

It is an arithmetic number, because the mean of its divisors is an integer number (2353536).

Almost surely, 2^21279454 is an apocalyptic number.

21279454 is a deficient number, since it is larger than the sum of its proper divisors (16377122).

21279454 is a wasteful number, since it uses less digits than its factorization.

21279454 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49071.

The product of its digits is 20160, while the sum is 34.

The square root of 21279454 is about 4612.9658572333. The cubic root of 21279454 is about 277.1108263798.

The spelling of 21279454 in words is "twenty-one million, two hundred seventy-nine thousand, four hundred fifty-four".