21274839 has 16 divisors (see below), whose sum is σ = 32889600. Its totient is φ = 13566168.

The previous prime is 21274831. The next prime is 21274861. The reversal of 21274839 is 93847212.

It is not a de Polignac number, because 21274839 - 2³ = 21274831 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21274831) 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 15 ways as a sum of consecutive naturals, for example, 16509 + ... + 17750.

It is an arithmetic number, because the mean of its divisors is an integer number (2055600).

Almost surely, 2^21274839 is an apocalyptic number.

21274839 is a deficient number, since it is larger than the sum of its proper divisors (11614761).

21274839 is a wasteful number, since it uses less digits than its factorization.

21274839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34291 (or 34285 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 21274839 is about 4612.4656096279. The cubic root of 21274839 is about 277.0907920480.

The spelling of 21274839 in words is "twenty-one million, two hundred seventy-four thousand, eight hundred thirty-nine".