81738136740 has 96 divisors (see below), whose sum is σ = 248775649920. Its totient is φ = 19932097536.

The previous prime is 81738136723. The next prime is 81738136817. The reversal of 81738136740 is 4763183718.

It is a super-2 number, since 2×81738136740² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81738136740.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 406225 + ... + 573144.

It is an arithmetic number, because the mean of its divisors is an integer number (2591413020).

Almost surely, 2^81738136740 is an apocalyptic number.

It is an amenable number.

81738136740 is an abundant number, since it is smaller than the sum of its proper divisors (167037513180).

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

81738136740 is a wasteful number, since it uses less digits than its factorization.

81738136740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 979501 (or 979499 counting only the distinct ones).

The product of its (nonzero) digits is 677376, while the sum is 48.

The spelling of 81738136740 in words is "eighty-one billion, seven hundred thirty-eight million, one hundred thirty-six thousand, seven hundred forty".