81013344740 has 24 divisors (see below), whose sum is σ = 171067965432. Its totient is φ = 32226301440.

The previous prime is 81013344677. The next prime is 81013344757. The reversal of 81013344740 is 4744331018.

It can be written as a sum of positive squares in 4 ways, for example, as 2096174656 + 78917170084 = 45784^2 + 280922^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 81013344740.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11186069 + ... + 11193308.

It is an arithmetic number, because the mean of its divisors is an integer number (7127831893).

Almost surely, 2^81013344740 is an apocalyptic number.

It is an amenable number.

81013344740 is an abundant number, since it is smaller than the sum of its proper divisors (90054620692).

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

81013344740 is a wasteful number, since it uses less digits than its factorization.

81013344740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22379567 (or 22379565 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 35.

Adding to 81013344740 its reverse (4744331018), we get a palindrome (85757675758).

The spelling of 81013344740 in words is "eighty-one billion, thirteen million, three hundred forty-four thousand, seven hundred forty".