81171766352 has 20 divisors (see below), whose sum is σ = 157449652116. Its totient is φ = 40539598080.

The previous prime is 81171766349. The next prime is 81171766363. The reversal of 81171766352 is 25366717118.

It can be written as a sum of positive squares in 2 ways, for example, as 71843297296 + 9328469056 = 268036^2 + 96584^2 .

It is a junction number, because it is equal to n+sod(n) for n = 81171766297 and 81171766306.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2878349 + ... + 2906412.

Almost surely, 2^81171766352 is an apocalyptic number.

It is an amenable number.

81171766352 is a deficient number, since it is larger than the sum of its proper divisors (76277885764).

81171766352 is a wasteful number, since it uses less digits than its factorization.

81171766352 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5785646 (or 5785640 counting only the distinct ones).

The product of its digits is 423360, while the sum is 47.

The spelling of 81171766352 in words is "eighty-one billion, one hundred seventy-one million, seven hundred sixty-six thousand, three hundred fifty-two".