21616025633506 has 8 divisors (see below), whose sum is σ = 34331334829740. Its totient is φ = 10172247356928.

The previous prime is 21616025633443. The next prime is 21616025633509. The reversal of 21616025633506 is 60533652061612.

It can be written as a sum of positive squares in 2 ways, for example, as 17181779398281 + 4434246235225 = 4145091^2 + 2105765^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21616025633509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 317882729871 + ... + 317882729938.

Almost surely, 2^{21616025633506} is an apocalyptic number.

21616025633506 is a deficient number, since it is larger than the sum of its proper divisors (12715309196234).

21616025633506 is a wasteful number, since it uses less digits than its factorization.

21616025633506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 635765459828.

The product of its (nonzero) digits is 1166400, while the sum is 46.

The spelling of 21616025633506 in words is "twenty-one trillion, six hundred sixteen billion, twenty-five million, six hundred thirty-three thousand, five hundred six".