21313412 has 6 divisors (see below), whose sum is σ = 37298478. Its totient is φ = 10656704.

The previous prime is 21313379. The next prime is 21313429. The reversal of 21313412 is 21431312.

It can be written as a sum of positive squares in only one way, i.e., 15476356 + 5837056 = 3934^2 + 2416^2 .

It is a zygodrome in base 3.

It is an unprimeable number.

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, 2664173 + ... + 2664180.

It is an arithmetic number, because the mean of its divisors is an integer number (6216413).

Almost surely, 2^21313412 is an apocalyptic number.

It is an amenable number.

21313412 is a deficient number, since it is larger than the sum of its proper divisors (15985066).

21313412 is a wasteful number, since it uses less digits than its factorization.

21313412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5328357 (or 5328355 counting only the distinct ones).

The product of its digits is 144, while the sum is 17.

The square root of 21313412 is about 4616.6451022360. The cubic root of 21313412 is about 277.2581535979.

Adding to 21313412 its reverse (21431312), we get a palindrome (42744724).

The spelling of 21313412 in words is "twenty-one million, three hundred thirteen thousand, four hundred twelve".