81317547042 has 48 divisors (see below), whose sum is σ = 164285698752. Its totient is φ = 26833433760.

The previous prime is 81317547037. The next prime is 81317547061. The reversal of 81317547042 is 24074571318.

It is a super-2 number, since 2×81317547042² (a number of 23 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 81317546985 and 81317547003.

It is a congruent number.

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 23 ways as a sum of consecutive naturals, for example, 79644492 + ... + 79645512.

It is an arithmetic number, because the mean of its divisors is an integer number (3422618724).

Almost surely, 2^81317547042 is an apocalyptic number.

81317547042 is an abundant number, since it is smaller than the sum of its proper divisors (82968151710).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81317547042 is a wasteful number, since it uses less digits than its factorization.

81317547042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2103 (or 1976 counting only the distinct ones).

The product of its (nonzero) digits is 188160, while the sum is 42.

The spelling of 81317547042 in words is "eighty-one billion, three hundred seventeen million, five hundred forty-seven thousand, forty-two".