21164056616 has 16 divisors (see below), whose sum is σ = 40355193600. Its totient is φ = 10402671664.

The previous prime is 21164056607. The next prime is 21164056637. The reversal of 21164056616 is 61665046112.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21164056616.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 22419080 + ... + 22420023.

It is an arithmetic number, because the mean of its divisors is an integer number (2522199600).

Almost surely, 2^21164056616 is an apocalyptic number.

It is an amenable number.

21164056616 is a deficient number, since it is larger than the sum of its proper divisors (19191136984).

21164056616 is a wasteful number, since it uses less digits than its factorization.

21164056616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44839168 (or 44839164 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 38.

The spelling of 21164056616 in words is "twenty-one billion, one hundred sixty-four million, fifty-six thousand, six hundred sixteen".