81963089 has 4 divisors (see below), whose sum is σ = 88267956. Its totient is φ = 75658224.

The previous prime is 81963071. The next prime is 81963097. The reversal of 81963089 is 98036918.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18490000 + 63473089 = 4300^2 + 7967^2 .

It is a cyclic number.

It is not a de Polignac number, because 81963089 - 2¹² = 81958993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81963989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3152414 + ... + 3152439.

It is an arithmetic number, because the mean of its divisors is an integer number (22066989).

Almost surely, 2^81963089 is an apocalyptic number.

It is an amenable number.

81963089 is a deficient number, since it is larger than the sum of its proper divisors (6304867).

81963089 is a wasteful number, since it uses less digits than its factorization.

81963089 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6304866.

The product of its (nonzero) digits is 93312, while the sum is 44.

The square root of 81963089 is about 9053.3468397052. The cubic root of 81963089 is about 434.3829521447.

The spelling of 81963089 in words is "eighty-one million, nine hundred sixty-three thousand, eighty-nine".