81381255078 has 16 divisors (see below), whose sum is σ = 162789768000. Its totient is φ = 27122542056.

The previous prime is 81381255077. The next prime is 81381255083. The reversal of 81381255078 is 87055218318.

It is a congruent 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 7 ways as a sum of consecutive naturals, for example, 1096828 + ... + 1168671.

It is an arithmetic number, because the mean of its divisors is an integer number (10174360500).

Almost surely, 2^81381255078 is an apocalyptic number.

81381255078 is an abundant number, since it is smaller than the sum of its proper divisors (81408512922).

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

81381255078 is a wasteful number, since it uses less digits than its factorization.

81381255078 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2271491.

The product of its (nonzero) digits is 537600, while the sum is 48.

The spelling of 81381255078 in words is "eighty-one billion, three hundred eighty-one million, two hundred fifty-five thousand, seventy-eight".