81031340742 has 48 divisors (see below), whose sum is σ = 178169070576. Its totient is φ = 24550257600.

The previous prime is 81031340737. The next prime is 81031340827. The reversal of 81031340742 is 24704313018.

It is a super-2 number, since 2×81031340742² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6659328 + ... + 6671484.

It is an arithmetic number, because the mean of its divisors is an integer number (3711855637).

Almost surely, 2^81031340742 is an apocalyptic number.

81031340742 is an abundant number, since it is smaller than the sum of its proper divisors (97137729834).

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

81031340742 is a wasteful number, since it uses less digits than its factorization.

81031340742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21365 (or 21354 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 33.

The spelling of 81031340742 in words is "eighty-one billion, thirty-one million, three hundred forty thousand, seven hundred forty-two".