81312526892 has 12 divisors (see below), whose sum is σ = 143556187656. Its totient is φ = 40296473280.

The previous prime is 81312526879. The next prime is 81312526907. The reversal of 81312526892 is 29862521318.

It is a happy number.

It is a super-2 number, since 2×81312526892² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 89947034 + ... + 89947937.

It is an arithmetic number, because the mean of its divisors is an integer number (11963015638).

Almost surely, 2^81312526892 is an apocalyptic number.

It is an amenable number.

81312526892 is a deficient number, since it is larger than the sum of its proper divisors (62243660764).

81312526892 is a wasteful number, since it uses less digits than its factorization.

81312526892 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179895088 (or 179895086 counting only the distinct ones).

The product of its digits is 414720, while the sum is 47.

The spelling of 81312526892 in words is "eighty-one billion, three hundred twelve million, five hundred twenty-six thousand, eight hundred ninety-two".