16505656532321 has 16 divisors (see below), whose sum is σ = 18959734622400. Its totient is φ = 14210994974400.

The previous prime is 16505656532251. The next prime is 16505656532353. The reversal of 16505656532321 is 12323565650561.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 16505656532321 - 2¹⁴ = 16505656515937 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16505656532321.

It is not an unprimeable number, because it can be changed into a prime (16505653532321) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11554070 + ... + 12903791.

It is an arithmetic number, because the mean of its divisors is an integer number (1184983413900).

Almost surely, 2^{16505656532321} is an apocalyptic number.

16505656532321 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16505656532321 is a deficient number, since it is larger than the sum of its proper divisors (2454078090079).

16505656532321 is a wasteful number, since it uses less digits than its factorization.

16505656532321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24461120.

The product of its (nonzero) digits is 4860000, while the sum is 50.

The spelling of 16505656532321 in words is "sixteen trillion, five hundred five billion, six hundred fifty-six million, five hundred thirty-two thousand, three hundred twenty-one".