21000788 has 12 divisors (see below), whose sum is σ = 36796032. Its totient is φ = 10487640.

The previous prime is 21000779. The next prime is 21000803. The reversal of 21000788 is 88700012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1181 + ... + 6587.

It is an arithmetic number, because the mean of its divisors is an integer number (3066336).

Almost surely, 2^21000788 is an apocalyptic number.

It is an amenable number.

21000788 is a deficient number, since it is larger than the sum of its proper divisors (15795244).

21000788 is a wasteful number, since it uses less digits than its factorization.

21000788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6382 (or 6380 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 26.

The square root of 21000788 is about 4582.6616719981. The cubic root of 21000788 is about 275.8958684398.

The spelling of 21000788 in words is "twenty-one million, seven hundred eighty-eight", and thus it is an aban number.