21033329985 has 24 divisors (see below), whose sum is σ = 38602348200. Its totient is φ = 10557906432.

The previous prime is 21033329981. The next prime is 21033330013. The reversal of 21033329985 is 58992333012.

21033329985 is a `hidden beast` number, since 21 + 0 + 333 + 299 + 8 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 4352832576 + 16680497409 = 65976^2 + 129153^2 .

It is not a de Polignac number, because 21033329985 - 2² = 21033329981 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 21033329985.

It is not an unprimeable number, because it can be changed into a prime (21033329981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13746510 + ... + 13748039.

It is an arithmetic number, because the mean of its divisors is an integer number (1608431175).

Almost surely, 2^21033329985 is an apocalyptic number.

It is an amenable number.

21033329985 is a deficient number, since it is larger than the sum of its proper divisors (17569018215).

21033329985 is a wasteful number, since it uses less digits than its factorization.

21033329985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27494577 (or 27494574 counting only the distinct ones).

The product of its (nonzero) digits is 349920, while the sum is 45.

The spelling of 21033329985 in words is "twenty-one billion, thirty-three million, three hundred twenty-nine thousand, nine hundred eighty-five".