21530229 has 32 divisors (see below), whose sum is σ = 34028544. Its totient is φ = 11854080.

The previous prime is 21530227. The next prime is 21530233. The reversal of 21530229 is 92203512.

It is not a de Polignac number, because 21530229 - 2¹ = 21530227 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21530199 and 21530208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21530227) 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, 101934 + ... + 102144.

It is an arithmetic number, because the mean of its divisors is an integer number (1063392).

Almost surely, 2^21530229 is an apocalyptic number.

It is an amenable number.

21530229 is a deficient number, since it is larger than the sum of its proper divisors (12498315).

21530229 is a wasteful number, since it uses less digits than its factorization.

21530229 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 377.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 21530229 is about 4640.0677796774. The cubic root of 21530229 is about 278.1951470415.

The spelling of 21530229 in words is "twenty-one million, five hundred thirty thousand, two hundred twenty-nine".