21812312 has 16 divisors (see below), whose sum is σ = 40950360. Its totient is φ = 10892224.

The previous prime is 21812279. The next prime is 21812353. The reversal of 21812312 is 21321812.

It is a super-3 number, since 3×21812312³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

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 in 3 ways as a sum of consecutive naturals, for example, 8348 + ... + 10644.

Almost surely, 2^21812312 is an apocalyptic number.

It is an amenable number.

21812312 is a deficient number, since it is larger than the sum of its proper divisors (19138048).

21812312 is a wasteful number, since it uses less digits than its factorization.

21812312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3490 (or 3486 counting only the distinct ones).

The product of its digits is 192, while the sum is 20.

The square root of 21812312 is about 4670.3652962054. The cubic root of 21812312 is about 279.4048242095.

The spelling of 21812312 in words is "twenty-one million, eight hundred twelve thousand, three hundred twelve".