21279027 has 32 divisors (see below), whose sum is σ = 35610624. Its totient is φ = 10980000.

The previous prime is 21278981. The next prime is 21279029. The reversal of 21279027 is 72097212.

It is a happy number.

It is not a de Polignac number, because 21279027 - 2⁶ = 21278963 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21278985 and 21279003.

It is not an unprimeable number, because it can be changed into a prime (21279029) 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 31 ways as a sum of consecutive naturals, for example, 57798 + ... + 58164.

It is an arithmetic number, because the mean of its divisors is an integer number (1112832).

Almost surely, 2^21279027 is an apocalyptic number.

21279027 is a deficient number, since it is larger than the sum of its proper divisors (14331597).

21279027 is a wasteful number, since it uses less digits than its factorization.

21279027 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 639.

The product of its (nonzero) digits is 3528, while the sum is 30.

The square root of 21279027 is about 4612.9195744127. The cubic root of 21279027 is about 277.1089728374.

The spelling of 21279027 in words is "twenty-one million, two hundred seventy-nine thousand, twenty-seven".