21646133316 has 36 divisors (see below), whose sum is σ = 55880802432. Its totient is φ = 7061858544.

The previous prime is 21646133297. The next prime is 21646133381. The reversal of 21646133316 is 61333164612.

21646133316 is a `hidden beast` number, since 2 + 1 + 6 + 4 + 613 + 3 + 31 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

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 11 ways as a sum of consecutive naturals, for example, 6394920 + ... + 6398303.

It is an arithmetic number, because the mean of its divisors is an integer number (1552244512).

Almost surely, 2^21646133316 is an apocalyptic number.

It is an amenable number.

21646133316 is an abundant number, since it is smaller than the sum of its proper divisors (34234669116).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21646133316 is a wasteful number, since it uses less digits than its factorization.

21646133316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12793280 (or 12793275 counting only the distinct ones).

The product of its digits is 46656, while the sum is 36.

Adding to 21646133316 its reverse (61333164612), we get a palindrome (82979297928).

The spelling of 21646133316 in words is "twenty-one billion, six hundred forty-six million, one hundred thirty-three thousand, three hundred sixteen".