21323310 has 16 divisors (see below), whose sum is σ = 51176016. Its totient is φ = 5686208.

The previous prime is 21323297. The next prime is 21323311. The reversal of 21323310 is 1332312.

It is a super-2 number, since 2×21323310² = 909367098712200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a zygodrome in base 9.

It is a self number, because there is not a number n which added to its sum of digits gives 21323310.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21323311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 355359 + ... + 355418.

It is an arithmetic number, because the mean of its divisors is an integer number (3198501).

Almost surely, 2^21323310 is an apocalyptic number.

21323310 is an abundant number, since it is smaller than the sum of its proper divisors (29852706).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21323310 is a wasteful number, since it uses less digits than its factorization.

21323310 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 710787.

The product of its (nonzero) digits is 108, while the sum is 15.

The square root of 21323310 is about 4617.7169683730. The cubic root of 21323310 is about 277.3010667409.

Adding to 21323310 its reverse (1332312), we get a palindrome (22655622).

The spelling of 21323310 in words is "twenty-one million, three hundred twenty-three thousand, three hundred ten".