16566531389 has 2 divisors, whose sum is σ = 16566531390. Its totient is φ = 16566531388.

The previous prime is 16566531277. The next prime is 16566531427. The reversal of 16566531389 is 98313566561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16566264100 + 267289 = 128710^2 + 517^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16566531389 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16566531389.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16566531089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8283265694 + 8283265695.

It is an arithmetic number, because the mean of its divisors is an integer number (8283265695).

Almost surely, 2^16566531389 is an apocalyptic number.

It is an amenable number.

16566531389 is a deficient number, since it is larger than the sum of its proper divisors (1).

16566531389 is an equidigital number, since it uses as much as digits as its factorization.

16566531389 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3499200, while the sum is 53.

The spelling of 16566531389 in words is "sixteen billion, five hundred sixty-six million, five hundred thirty-one thousand, three hundred eighty-nine".