21818229 has 8 divisors (see below), whose sum is σ = 29500992. Its totient is φ = 14340480.

The previous prime is 21818227. The next prime is 21818267. The reversal of 21818229 is 92281812.

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

It is not a de Polignac number, because 21818229 - 2¹ = 21818227 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21818229.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21818221) 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, 51004 + ... + 51429.

It is an arithmetic number, because the mean of its divisors is an integer number (3687624).

Almost surely, 2^21818229 is an apocalyptic number.

It is an amenable number.

21818229 is a deficient number, since it is larger than the sum of its proper divisors (7682763).

21818229 is a wasteful number, since it uses less digits than its factorization.

21818229 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102507.

The product of its digits is 4608, while the sum is 33.

The square root of 21818229 is about 4670.9987154783. The cubic root of 21818229 is about 279.4300865305.

The spelling of 21818229 in words is "twenty-one million, eight hundred eighteen thousand, two hundred twenty-nine".