21029229 has 12 divisors (see below), whose sum is σ = 32712316. Its totient is φ = 12940992.

The previous prime is 21029207. The next prime is 21029237. The reversal of 21029229 is 92292012.

It can be written as a sum of positive squares in 2 ways, for example, as 9455625 + 11573604 = 3075^2 + 3402^2 .

It is not a de Polignac number, because 21029229 - 2⁷ = 21029101 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21029249) 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 11 ways as a sum of consecutive naturals, for example, 89752 + ... + 89985.

Almost surely, 2^21029229 is an apocalyptic number.

It is an amenable number.

21029229 is a deficient number, since it is larger than the sum of its proper divisors (11683087).

21029229 is a wasteful number, since it uses less digits than its factorization.

21029229 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179756 (or 179753 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 21029229 is about 4585.7637313756. The cubic root of 21029229 is about 276.0203592417.

The spelling of 21029229 in words is "twenty-one million, twenty-nine thousand, two hundred twenty-nine".