81741840077 has 8 divisors (see below), whose sum is σ = 83972660376. Its totient is φ = 79512155712.

The previous prime is 81741840043. The next prime is 81741840107. The reversal of 81741840077 is 77004814718.

It can be written as a sum of positive squares in 4 ways, for example, as 36795296041 + 44946544036 = 191821^2 + 212006^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81741840077 - 2¹⁸ = 81741577933 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81741810077) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 137078 + ... + 426935.

It is an arithmetic number, because the mean of its divisors is an integer number (10496582547).

Almost surely, 2^81741840077 is an apocalyptic number.

It is an amenable number.

81741840077 is a deficient number, since it is larger than the sum of its proper divisors (2230820299).

81741840077 is a wasteful number, since it uses less digits than its factorization.

81741840077 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 567967.

The product of its (nonzero) digits is 351232, while the sum is 47.

The spelling of 81741840077 in words is "eighty-one billion, seven hundred forty-one million, eight hundred forty thousand, seventy-seven".