21069912 has 32 divisors (see below), whose sum is σ = 53798400. Its totient is φ = 6873504.

The previous prime is 21069901. The next prime is 21069929. The reversal of 21069912 is 21996012.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21069912.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 8212 + ... + 10467.

It is an arithmetic number, because the mean of its divisors is an integer number (1681200).

Almost surely, 2^21069912 is an apocalyptic number.

It is an amenable number.

21069912 is an abundant number, since it is smaller than the sum of its proper divisors (32728488).

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

21069912 is a wasteful number, since it uses less digits than its factorization.

21069912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18735 (or 18731 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 21069912 is about 4590.1973813770. The cubic root of 21069912 is about 276.1982402702.

The spelling of 21069912 in words is "twenty-one million, sixty-nine thousand, nine hundred twelve".