21304113 has 16 divisors (see below), whose sum is σ = 29245440. Its totient is φ = 13787856.

The previous prime is 21304109. The next prime is 21304117. The reversal of 21304113 is 31140312.

It is an interprime number because it is at equal distance from previous prime (21304109) and next prime (21304117).

It is not a de Polignac number, because 21304113 - 2² = 21304109 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21304092 and 21304101.

It is not an unprimeable number, because it can be changed into a prime (21304117) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19056 + ... + 20142.

It is an arithmetic number, because the mean of its divisors is an integer number (1827840).

Almost surely, 2^21304113 is an apocalyptic number.

It is an amenable number.

21304113 is a deficient number, since it is larger than the sum of its proper divisors (7941327).

21304113 is a wasteful number, since it uses less digits than its factorization.

21304113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1276.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 21304113 is about 4615.6378757437. The cubic root of 21304113 is about 277.2178253354.

Adding to 21304113 its sum of digits (15), we get a triangular number (21304128 = T₆₅₂₇).

Adding to 21304113 its reverse (31140312), we get a palindrome (52444425).

The spelling of 21304113 in words is "twenty-one million, three hundred four thousand, one hundred thirteen".