81381420813814 has 48 divisors (see below), whose sum is σ = 135745798406400. Its totient is φ = 36561918294000.

The previous prime is 81381420813769. The next prime is 81381420813827. The reversal of 81381420813814 is 41831802418318.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1676217 + ... + 12867499.

It is an arithmetic number, because the mean of its divisors is an integer number (2828037466800).

Almost surely, 2^{81381420813814} is an apocalyptic number.

81381420813814 is a deficient number, since it is larger than the sum of its proper divisors (54364377592586).

81381420813814 is a wasteful number, since it uses less digits than its factorization.

81381420813814 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11191657 (or 11191646 counting only the distinct ones).

The product of its (nonzero) digits is 1179648, while the sum is 52.

The spelling of 81381420813814 in words is "eighty-one trillion, three hundred eighty-one billion, four hundred twenty million, eight hundred thirteen thousand, eight hundred fourteen".