81407288089 has 4 divisors (see below), whose sum is σ = 81762778660. Its totient is φ = 81051797520.

The previous prime is 81407288069. The next prime is 81407288111. The reversal of 81407288089 is 98088270418.

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 58399555600 + 23007732489 = 241660^2 + 151683^2 .

It is a cyclic number.

It is not a de Polignac number, because 81407288089 - 2¹⁷ = 81407157017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81407288069) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 177744942 + ... + 177745399.

It is an arithmetic number, because the mean of its divisors is an integer number (20440694665).

Almost surely, 2^81407288089 is an apocalyptic number.

It is an amenable number.

81407288089 is a deficient number, since it is larger than the sum of its proper divisors (355490571).

81407288089 is a wasteful number, since it uses less digits than its factorization.

81407288089 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 355490570.

The product of its (nonzero) digits is 2064384, while the sum is 55.

The spelling of 81407288089 in words is "eighty-one billion, four hundred seven million, two hundred eighty-eight thousand, eighty-nine".