21272229 has 48 divisors (see below), whose sum is σ = 36241920. Its totient is φ = 11884320.

The previous prime is 21272213. The next prime is 21272269. The reversal of 21272229 is 92227212.

It is not a de Polignac number, because 21272229 - 2⁴ = 21272213 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21272269) 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 47 ways as a sum of consecutive naturals, for example, 80752 + ... + 81014.

It is an arithmetic number, because the mean of its divisors is an integer number (755040).

Almost surely, 2^21272229 is an apocalyptic number.

It is an amenable number.

21272229 is a deficient number, since it is larger than the sum of its proper divisors (14969691).

21272229 is a wasteful number, since it uses less digits than its factorization.

21272229 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 342 (or 339 counting only the distinct ones).

The product of its digits is 2016, while the sum is 27.

The square root of 21272229 is about 4612.1826720112. The cubic root of 21272229 is about 277.0794604065.

It can be divided in two parts, 2127 and 2229, that added together give a square (4356 = 66²).

The spelling of 21272229 in words is "twenty-one million, two hundred seventy-two thousand, two hundred twenty-nine".