81865266054 has 128 divisors (see below), whose sum is σ = 198923268096. Its totient is φ = 22120128000.

The previous prime is 81865266031. The next prime is 81865266143. The reversal of 81865266054 is 45066256818.

It is a junction number, because it is equal to n+sod(n) for n = 81865265988 and 81865266006.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 16302064 + ... + 16307084.

It is an arithmetic number, because the mean of its divisors is an integer number (1554088032).

Almost surely, 2^81865266054 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81865266054, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99461634048).

81865266054 is an abundant number, since it is smaller than the sum of its proper divisors (117058002042).

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

81865266054 is a wasteful number, since it uses less digits than its factorization.

81865266054 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5694.

The product of its (nonzero) digits is 2764800, while the sum is 51.

The spelling of 81865266054 in words is "eighty-one billion, eight hundred sixty-five million, two hundred sixty-six thousand, fifty-four".