21785446064 has 20 divisors (see below), whose sum is σ = 42787513656. Its totient is φ = 10743507072.

The previous prime is 21785445971. The next prime is 21785446129. The reversal of 21785446064 is 46064458712.

It is a happy number.

It is a hoax number, since the sum of its digits (47) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9324794 + ... + 9327129.

Almost surely, 2^21785446064 is an apocalyptic number.

It is an amenable number.

21785446064 is a deficient number, since it is larger than the sum of its proper divisors (21002067592).

21785446064 is a wasteful number, since it uses less digits than its factorization.

21785446064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18652004 (or 18651998 counting only the distinct ones).

The product of its (nonzero) digits is 1290240, while the sum is 47.

The spelling of 21785446064 in words is "twenty-one billion, seven hundred eighty-five million, four hundred forty-six thousand, sixty-four".