21232812 has 12 divisors (see below), whose sum is σ = 49543256. Its totient is φ = 7077600.

The previous prime is 21232781. The next prime is 21232817. The reversal of 21232812 is 21823212.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (21232817) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 884689 + ... + 884712.

Almost surely, 2^21232812 is an apocalyptic number.

It is an amenable number.

21232812 is an abundant number, since it is smaller than the sum of its proper divisors (28310444).

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

21232812 is a wasteful number, since it uses less digits than its factorization.

21232812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1769408 (or 1769406 counting only the distinct ones).

The product of its digits is 384, while the sum is 21.

The square root of 21232812 is about 4607.9075511559. The cubic root of 21232812 is about 276.9082137559.

The spelling of 21232812 in words is "twenty-one million, two hundred thirty-two thousand, eight hundred twelve".