81178595213 has 8 divisors (see below), whose sum is σ = 81258614880. Its totient is φ = 81098609040.

The previous prime is 81178595209. The next prime is 81178595227. The reversal of 81178595213 is 31259587118.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81178595213 - 2² = 81178595209 is a prime.

It is a super-2 number, since 2×81178595213² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81178595233) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9921158 + ... + 9929336.

It is an arithmetic number, because the mean of its divisors is an integer number (10157326860).

Almost surely, 2^81178595213 is an apocalyptic number.

It is an amenable number.

81178595213 is a deficient number, since it is larger than the sum of its proper divisors (80019667).

81178595213 is a wasteful number, since it uses less digits than its factorization.

81178595213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16747.

The product of its digits is 604800, while the sum is 50.

The spelling of 81178595213 in words is "eighty-one billion, one hundred seventy-eight million, five hundred ninety-five thousand, two hundred thirteen".