21022312 has 8 divisors (see below), whose sum is σ = 39416850. Its totient is φ = 10511152.

The previous prime is 21022279. The next prime is 21022357. The reversal of 21022312 is 21322012.

It can be written as a sum of positive squares in only one way, i.e., 16208676 + 4813636 = 4026^2 + 2194^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 21022292 and 21022301.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1313887 + ... + 1313902.

Almost surely, 2^21022312 is an apocalyptic number.

It is an amenable number.

21022312 is a deficient number, since it is larger than the sum of its proper divisors (18394538).

21022312 is a wasteful number, since it uses less digits than its factorization.

21022312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2627795 (or 2627791 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 21022312 is about 4585.0094874493. The cubic root of 21022312 is about 275.9900927621.

Adding to 21022312 its reverse (21322012), we get a palindrome (42344324).

It can be divided in two parts, 210 and 22312, that added together give a palindrome (22522).

The spelling of 21022312 in words is "twenty-one million, twenty-two thousand, three hundred twelve".