81381255076 has 27 divisors (see below), whose sum is σ = 156553289067. Its totient is φ = 36988626840.

The previous prime is 81381255013. The next prime is 81381255077. The reversal of 81381255076 is 67055218318.

The square root of 81381255076 is 285274.

It is a perfect power (a square), and thus also a powerful number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81381255077) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 6269545 + ... + 6282511.

Almost surely, 2^81381255076 is an apocalyptic number.

81381255076 is the 285274-th square number.

It is an amenable number.

81381255076 is a deficient number, since it is larger than the sum of its proper divisors (75172033991).

81381255076 is an equidigital number, since it uses as much as digits as its factorization.

81381255076 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25960 (or 12980 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 46.

The spelling of 81381255076 in words is "eighty-one billion, three hundred eighty-one million, two hundred fifty-five thousand, seventy-six".