81089507399 has 4 divisors (see below), whose sum is σ = 81118460400. Its totient is φ = 81060554400.

The previous prime is 81089507393. The next prime is 81089507449. The reversal of 81089507399 is 99370598018.

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

It is a cyclic number.

It is not a de Polignac number, because 81089507399 - 2³² = 76794540103 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81089507393) 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, 14472299 + ... + 14477900.

It is an arithmetic number, because the mean of its divisors is an integer number (20279615100).

Almost surely, 2^81089507399 is an apocalyptic number.

81089507399 is a deficient number, since it is larger than the sum of its proper divisors (28953001).

81089507399 is a wasteful number, since it uses less digits than its factorization.

81089507399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28953000.

The product of its (nonzero) digits is 4898880, while the sum is 59.

The spelling of 81089507399 in words is "eighty-one billion, eighty-nine million, five hundred seven thousand, three hundred ninety-nine".