81071659152 has 180 divisors, whose sum is σ = 249955077372. Its totient is φ = 24511449600.

The previous prime is 81071659147. The next prime is 81071659199. The reversal of 81071659152 is 25195617018.

81071659152 is a `hidden beast` number, since 8 + 1 + 0 + 7 + 1 + 6 + 591 + 52 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 33519751056 + 47551908096 = 183084^2 + 218064^2 .

It is a super-2 number, since 2×81071659152² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81071659098 and 81071659107.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 8027418 + ... + 8037510.

Almost surely, 2^81071659152 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 81071659152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124977538686).

81071659152 is an abundant number, since it is smaller than the sum of its proper divisors (168883418220).

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

81071659152 is a wasteful number, since it uses less digits than its factorization.

81071659152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10590 (or 10570 counting only the distinct ones).

The product of its (nonzero) digits is 151200, while the sum is 45.

The spelling of 81071659152 in words is "eighty-one billion, seventy-one million, six hundred fifty-nine thousand, one hundred fifty-two".