21206204 has 12 divisors (see below), whose sum is σ = 39064200. Its totient is φ = 10045008.

The previous prime is 21206189. The next prime is 21206219. The reversal of 21206204 is 40260212.

It is an interprime number because it is at equal distance from previous prime (21206189) and next prime (21206219).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 139439 + ... + 139590.

It is an arithmetic number, because the mean of its divisors is an integer number (3255350).

Almost surely, 2^21206204 is an apocalyptic number.

It is an amenable number.

21206204 is a deficient number, since it is larger than the sum of its proper divisors (17857996).

21206204 is a wasteful number, since it uses less digits than its factorization.

21206204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 279052 (or 279050 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 21206204 is about 4605.0194353553. The cubic root of 21206204 is about 276.7924957871.

Adding to 21206204 its reverse (40260212), we get a palindrome (61466416).

The spelling of 21206204 in words is "twenty-one million, two hundred six thousand, two hundred four".