16221603661321 has 16 divisors (see below), whose sum is σ = 16369493454720. Its totient is φ = 16074319829760.

The previous prime is 16221603661273. The next prime is 16221603661357. The reversal of 16221603661321 is 12316630612261.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16221603661321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16221603661381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 379227291 + ... + 379270063.

It is an arithmetic number, because the mean of its divisors is an integer number (1023093340920).

Almost surely, 2^{16221603661321} is an apocalyptic number.

It is an amenable number.

16221603661321 is a deficient number, since it is larger than the sum of its proper divisors (147889793399).

16221603661321 is a wasteful number, since it uses less digits than its factorization.

16221603661321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49776.

The product of its (nonzero) digits is 93312, while the sum is 40.

The spelling of 16221603661321 in words is "sixteen trillion, two hundred twenty-one billion, six hundred three million, six hundred sixty-one thousand, three hundred twenty-one".