81351230688 has 384 divisors, whose sum is σ = 301459415040. Its totient is φ = 20762542080.

The previous prime is 81351230683. The next prime is 81351230717. The reversal of 81351230688 is 88603215318.

81351230688 is a `hidden beast` number, since 8 + 1 + 351 + 230 + 68 + 8 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81351230683) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2420656 + ... + 2454032.

It is an arithmetic number, because the mean of its divisors is an integer number (785050560).

Almost surely, 2^81351230688 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 81351230688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (150729707520).

81351230688 is an abundant number, since it is smaller than the sum of its proper divisors (220108184352).

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

81351230688 is a wasteful number, since it uses less digits than its factorization.

81351230688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33447 (or 33433 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 45.

The spelling of 81351230688 in words is "eighty-one billion, three hundred fifty-one million, two hundred thirty thousand, six hundred eighty-eight".