21331306 has 8 divisors (see below), whose sum is σ = 32296320. Its totient is φ = 10565868.

The previous prime is 21331283. The next prime is 21331309. The reversal of 21331306 is 60313312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21331309) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49626 + ... + 50053.

It is an arithmetic number, because the mean of its divisors is an integer number (4037040).

Almost surely, 2^21331306 is an apocalyptic number.

21331306 is a deficient number, since it is larger than the sum of its proper divisors (10965014).

21331306 is a wasteful number, since it uses less digits than its factorization.

21331306 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99788.

The product of its (nonzero) digits is 324, while the sum is 19.

The square root of 21331306 is about 4618.5826830317. The cubic root of 21331306 is about 277.3357239968.

Adding to 21331306 its reverse (60313312), we get a palindrome (81644618).

The spelling of 21331306 in words is "twenty-one million, three hundred thirty-one thousand, three hundred six".