21304156 has 12 divisors (see below), whose sum is σ = 38290168. Its totient is φ = 10364112.

The previous prime is 21304147. The next prime is 21304219. The reversal of 21304156 is 65140312.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 71826 + ... + 72121.

Almost surely, 2^21304156 is an apocalyptic number.

It is an amenable number.

21304156 is a deficient number, since it is larger than the sum of its proper divisors (16986012).

21304156 is a wasteful number, since it uses less digits than its factorization.

21304156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143988 (or 143986 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 21304156 is about 4615.6425338191. The cubic root of 21304156 is about 277.2180118465.

Adding to 21304156 its reverse (65140312), we get a palindrome (86444468).

The spelling of 21304156 in words is "twenty-one million, three hundred four thousand, one hundred fifty-six".