21308302 has 4 divisors (see below), whose sum is σ = 31962456. Its totient is φ = 10654150.

The previous prime is 21308299. The next prime is 21308303. The reversal of 21308302 is 20380312.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21308302.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21308303) by changing a digit.

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 as a sum of consecutive naturals, namely, 5327074 + ... + 5327077.

It is an arithmetic number, because the mean of its divisors is an integer number (7990614).

Almost surely, 2^21308302 is an apocalyptic number.

21308302 is a deficient number, since it is larger than the sum of its proper divisors (10654154).

21308302 is a wasteful number, since it uses less digits than its factorization.

21308302 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10654153.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 21308302 is about 4616.0916368720. The cubic root of 21308302 is about 277.2359938046.

Adding to 21308302 its reverse (20380312), we get a palindrome (41688614).

The spelling of 21308302 in words is "twenty-one million, three hundred eight thousand, three hundred two".