21204229 has 8 divisors (see below), whose sum is σ = 22220352. Its totient is φ = 20196000.

The previous prime is 21204223. The next prime is 21204241. The reversal of 21204229 is 92240212.

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

It is a cyclic number.

It is not a de Polignac number, because 21204229 - 2⁹ = 21203717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21204223) 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, 3937 + ... + 7609.

It is an arithmetic number, because the mean of its divisors is an integer number (2777544).

Almost surely, 2^21204229 is an apocalyptic number.

It is an amenable number.

21204229 is a deficient number, since it is larger than the sum of its proper divisors (1016123).

21204229 is a wasteful number, since it uses less digits than its factorization.

21204229 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3947.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 21204229 is about 4604.8049904420. The cubic root of 21204229 is about 276.7839026705.

The spelling of 21204229 in words is "twenty-one million, two hundred four thousand, two hundred twenty-nine".