21063812 has 24 divisors (see below), whose sum is σ = 45958080. Its totient is φ = 8206560.

The previous prime is 21063803. The next prime is 21063817. The reversal of 21063812 is 21836012.

It is not an unprimeable number, because it can be changed into a prime (21063817) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33887 + ... + 34502.

It is an arithmetic number, because the mean of its divisors is an integer number (1914920).

Almost surely, 2^21063812 is an apocalyptic number.

21063812 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21063812 is an abundant number, since it is smaller than the sum of its proper divisors (24894268).

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

21063812 is a wasteful number, since it uses less digits than its factorization.

21063812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68411 (or 68409 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 21063812 is about 4589.5328738337. The cubic root of 21063812 is about 276.1715834292.

Adding to 21063812 its reverse (21836012), we get a palindrome (42899824).

The spelling of 21063812 in words is "twenty-one million, sixty-three thousand, eight hundred twelve".