81000813740 has 48 divisors (see below), whose sum is σ = 212074861824. Its totient is φ = 25247006400.

The previous prime is 81000813739. The next prime is 81000813749. The reversal of 81000813740 is 4731800018.

It is a super-2 number, since 2×81000813740² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81000813697 and 81000813706.

It is not an unprimeable number, because it can be changed into a prime (81000813749) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26297426 + ... + 26300505.

It is an arithmetic number, because the mean of its divisors is an integer number (4418226288).

Almost surely, 2^81000813740 is an apocalyptic number.

It is an amenable number.

81000813740 is an abundant number, since it is smaller than the sum of its proper divisors (131074048084).

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

81000813740 is a wasteful number, since it uses less digits than its factorization.

81000813740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52597958 (or 52597956 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 32.

The spelling of 81000813740 in words is "eighty-one billion, eight hundred thirteen thousand, seven hundred forty".