81171827052 has 48 divisors (see below), whose sum is σ = 201250933632. Its totient is φ = 25375668480.

The previous prime is 81171827039. The next prime is 81171827063. The reversal of 81171827052 is 25072817118.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 81171826995 and 81171827013.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 645274 + ... + 760737.

It is an arithmetic number, because the mean of its divisors is an integer number (4192727784).

Almost surely, 2^81171827052 is an apocalyptic number.

It is an amenable number.

81171827052 is an abundant number, since it is smaller than the sum of its proper divisors (120079106580).

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

81171827052 is a wasteful number, since it uses less digits than its factorization.

81171827052 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1406318 (or 1406316 counting only the distinct ones).

The product of its (nonzero) digits is 62720, while the sum is 42.

The spelling of 81171827052 in words is "eighty-one billion, one hundred seventy-one million, eight hundred twenty-seven thousand, fifty-two".