21304402 has 16 divisors (see below), whose sum is σ = 37037952. Its totient is φ = 9001440.

The previous prime is 21304397. The next prime is 21304427. The reversal of 21304402 is 20440312.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9723 + ... + 11710.

It is an arithmetic number, because the mean of its divisors is an integer number (2314872).

Almost surely, 2^21304402 is an apocalyptic number.

21304402 is a deficient number, since it is larger than the sum of its proper divisors (15733550).

21304402 is a wasteful number, since it uses less digits than its factorization.

21304402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21513.

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 21304402 is about 4615.6691822530. The cubic root of 21304402 is about 277.2190788584.

Adding to 21304402 its reverse (20440312), we get a palindrome (41744714).

The spelling of 21304402 in words is "twenty-one million, three hundred four thousand, four hundred two".