21173229 has 24 divisors (see below), whose sum is σ = 38131392. Its totient is φ = 10998720.

The previous prime is 21173221. The next prime is 21173231. The reversal of 21173229 is 92237112.

It is not a de Polignac number, because 21173229 - 2³ = 21173221 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21173221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14584 + ... + 15969.

It is an arithmetic number, because the mean of its divisors is an integer number (1588808).

Almost surely, 2^21173229 is an apocalyptic number.

It is an amenable number.

21173229 is a deficient number, since it is larger than the sum of its proper divisors (16958163).

21173229 is a wasteful number, since it uses less digits than its factorization.

21173229 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30577 (or 30574 counting only the distinct ones).

The product of its digits is 1512, while the sum is 27.

The square root of 21173229 is about 4601.4377101076. The cubic root of 21173229 is about 276.6489533989.

The spelling of 21173229 in words is "twenty-one million, one hundred seventy-three thousand, two hundred twenty-nine".