21272839 has 8 divisors (see below), whose sum is σ = 24383520. Its totient is φ = 18180096.

The previous prime is 21272821. The next prime is 21272843. The reversal of 21272839 is 93827212.

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

It is a cyclic number.

It is not a de Polignac number, because 21272839 - 2⁹ = 21272327 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21272819) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1834 + ... + 6775.

It is an arithmetic number, because the mean of its divisors is an integer number (3047940).

Almost surely, 2^21272839 is an apocalyptic number.

21272839 is a deficient number, since it is larger than the sum of its proper divisors (3110681).

21272839 is an equidigital number, since it uses as much as digits as its factorization.

21272839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8969.

The product of its digits is 12096, while the sum is 34.

The square root of 21272839 is about 4612.2488007479. The cubic root of 21272839 is about 277.0821088808.

The spelling of 21272839 in words is "twenty-one million, two hundred seventy-two thousand, eight hundred thirty-nine".