16326553561 has 2 divisors, whose sum is σ = 16326553562. Its totient is φ = 16326553560.

The previous prime is 16326553549. The next prime is 16326553583. The reversal of 16326553561 is 16535562361.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11136791961 + 5189761600 = 105531^2 + 72040^2 .

It is a cyclic number.

It is not a de Polignac number, because 16326553561 - 2⁹ = 16326553049 is a prime.

It is not a weakly prime, because it can be changed into another prime (16326553531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8163276780 + 8163276781.

It is an arithmetic number, because the mean of its divisors is an integer number (8163276781).

Almost surely, 2^16326553561 is an apocalyptic number.

It is an amenable number.

16326553561 is a deficient number, since it is larger than the sum of its proper divisors (1).

16326553561 is an equidigital number, since it uses as much as digits as its factorization.

16326553561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 486000, while the sum is 43.

The spelling of 16326553561 in words is "sixteen billion, three hundred twenty-six million, five hundred fifty-three thousand, five hundred sixty-one".