21244312 has 8 divisors (see below), whose sum is σ = 39833100. Its totient is φ = 10622152.

The previous prime is 21244309. The next prime is 21244367. The reversal of 21244312 is 21344212.

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 21244312.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1327762 + ... + 1327777.

Almost surely, 2^21244312 is an apocalyptic number.

It is an amenable number.

21244312 is a deficient number, since it is larger than the sum of its proper divisors (18588788).

21244312 is a wasteful number, since it uses less digits than its factorization.

21244312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2655545 (or 2655541 counting only the distinct ones).

The product of its digits is 384, while the sum is 19.

The square root of 21244312 is about 4609.1552371340. The cubic root of 21244312 is about 276.9581972393.

Adding to 21244312 its reverse (21344212), we get a palindrome (42588524).

The spelling of 21244312 in words is "twenty-one million, two hundred forty-four thousand, three hundred twelve".