81086898409 has 4 divisors (see below), whose sum is σ = 88458434640. Its totient is φ = 73715362180.

The previous prime is 81086898371. The next prime is 81086898419. The reversal of 81086898409 is 90489868018.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81086898409 - 2³³ = 72496963817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81086898419) 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, 3685768099 + ... + 3685768120.

It is an arithmetic number, because the mean of its divisors is an integer number (22114608660).

Almost surely, 2^81086898409 is an apocalyptic number.

It is an amenable number.

81086898409 is a deficient number, since it is larger than the sum of its proper divisors (7371536231).

81086898409 is a wasteful number, since it uses less digits than its factorization.

81086898409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7371536230.

The product of its (nonzero) digits is 7962624, while the sum is 61.

The spelling of 81086898409 in words is "eighty-one billion, eighty-six million, eight hundred ninety-eight thousand, four hundred nine".