81173090858 has 8 divisors (see below), whose sum is σ = 121962909600. Its totient is φ = 40518787660.

The previous prime is 81173090797. The next prime is 81173090899. The reversal of 81173090858 is 85809037118.

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

It is a super-2 number, since 2×81173090858² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33877388 + ... + 33879783.

It is an arithmetic number, because the mean of its divisors is an integer number (15245363700).

Almost surely, 2^81173090858 is an apocalyptic number.

81173090858 is a deficient number, since it is larger than the sum of its proper divisors (40789818742).

81173090858 is a wasteful number, since it uses less digits than its factorization.

81173090858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67757772.

The product of its (nonzero) digits is 483840, while the sum is 50.

The spelling of 81173090858 in words is "eighty-one billion, one hundred seventy-three million, ninety thousand, eight hundred fifty-eight".