21279849 has 8 divisors (see below), whose sum is σ = 28475232. Its totient is φ = 14135520.

The previous prime is 21279833. The next prime is 21279851. The reversal of 21279849 is 94897212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21279849 - 2⁴ = 21279833 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21279849.

It is not an unprimeable number, because it can be changed into a prime (21279809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11779 + ... + 13464.

It is an arithmetic number, because the mean of its divisors is an integer number (3559404).

Almost surely, 2^21279849 is an apocalyptic number.

It is an amenable number.

21279849 is a deficient number, since it is larger than the sum of its proper divisors (7195383).

21279849 is a wasteful number, since it uses less digits than its factorization.

21279849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25527.

The product of its digits is 72576, while the sum is 42.

The square root of 21279849 is about 4613.0086711386. The cubic root of 21279849 is about 277.1125409930.

The spelling of 21279849 in words is "twenty-one million, two hundred seventy-nine thousand, eight hundred forty-nine".