81906801242112 has 936 divisors, whose sum is σ = 305164073842992. Its totient is φ = 20925421977600.

The previous prime is 81906801242069. The next prime is 81906801242117. The reversal of 81906801242112 is 21124210860918.

81906801242112 is a `hidden beast` number, since 81 + 90 + 68 + 0 + 1 + 2 + 421 + 1 + 2 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81906801242117) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1212017668 + ... + 1212085244.

It is an arithmetic number, because the mean of its divisors is an integer number (326029993422).

Almost surely, 2^{81906801242112} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81906801242112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (152582036921496).

81906801242112 is an abundant number, since it is smaller than the sum of its proper divisors (223257272600880).

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

81906801242112 is a wasteful number, since it uses less digits than its factorization.

81906801242112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67693 (or 67661 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 45.

The spelling of 81906801242112 in words is "eighty-one trillion, nine hundred six billion, eight hundred one million, two hundred forty-two thousand, one hundred twelve".