16441947581 has 2 divisors, whose sum is σ = 16441947582. Its totient is φ = 16441947580.

The previous prime is 16441947547. The next prime is 16441947659. The reversal of 16441947581 is 18574914461.

16441947581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12558788356 + 3883159225 = 112066^2 + 62315^2 .

It is an emirp because it is prime and its reverse (18574914461) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16441947581 is a prime.

It is a super-3 number, since 3×16441947581³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16441947541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8220973790 + 8220973791.

It is an arithmetic number, because the mean of its divisors is an integer number (8220973791).

Almost surely, 2^16441947581 is an apocalyptic number.

It is an amenable number.

16441947581 is a deficient number, since it is larger than the sum of its proper divisors (1).

16441947581 is an equidigital number, since it uses as much as digits as its factorization.

16441947581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 967680, while the sum is 50.

The spelling of 16441947581 in words is "sixteen billion, four hundred forty-one million, nine hundred forty-seven thousand, five hundred eighty-one".