21103012 has 12 divisors (see below), whose sum is σ = 42206080. Its totient is φ = 9044136.

The previous prime is 21103003. The next prime is 21103021. The reversal of 21103012 is 21030112.

It is an interprime number because it is at equal distance from previous prime (21103003) and next prime (21103021).

21103012 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 21103012.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 376812 + ... + 376867.

Almost surely, 2^21103012 is an apocalyptic number.

It is an amenable number.

21103012 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21103012 is a wasteful number, since it uses less digits than its factorization.

21103012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 753690 (or 753688 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 21103012 is about 4593.8014759021. The cubic root of 21103012 is about 276.3427967765.

Adding to 21103012 its reverse (21030112), we get a palindrome (42133124).

Subtracting from 21103012 its reverse (21030112), we obtain a square (72900 = 270²).

The spelling of 21103012 in words is "twenty-one million, one hundred three thousand, twelve".