21059788 has 12 divisors (see below), whose sum is σ = 38043712. Its totient is φ = 10190160.

The previous prime is 21059761. The next prime is 21059791. The reversal of 21059788 is 88795012.

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 21059788.

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, 84795 + ... + 85042.

Almost surely, 2^21059788 is an apocalyptic number.

It is an amenable number.

21059788 is a deficient number, since it is larger than the sum of its proper divisors (16983924).

21059788 is a wasteful number, since it uses less digits than its factorization.

21059788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169872 (or 169870 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 40.

The square root of 21059788 is about 4589.0944640528. The cubic root of 21059788 is about 276.1539958367.

The spelling of 21059788 in words is "twenty-one million, fifty-nine thousand, seven hundred eighty-eight".