16620601321 has 2 divisors, whose sum is σ = 16620601322. Its totient is φ = 16620601320.

The previous prime is 16620601267. The next prime is 16620601331. The reversal of 16620601321 is 12310602661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16181112025 + 439489296 = 127205^2 + 20964^2 .

It is a cyclic number.

It is not a de Polignac number, because 16620601321 - 2⁹ = 16620600809 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16620601321.

It is not a weakly prime, because it can be changed into another prime (16620601331) 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 as a sum of consecutive naturals, namely, 8310300660 + 8310300661.

It is an arithmetic number, because the mean of its divisors is an integer number (8310300661).

Almost surely, 2^16620601321 is an apocalyptic number.

It is an amenable number.

16620601321 is a deficient number, since it is larger than the sum of its proper divisors (1).

16620601321 is an equidigital number, since it uses as much as digits as its factorization.

16620601321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 28.

The spelling of 16620601321 in words is "sixteen billion, six hundred twenty million, six hundred one thousand, three hundred twenty-one".