81161504748 has 36 divisors (see below), whose sum is σ = 214078174128. Its totient is φ = 25877580960.

The previous prime is 81161504747. The next prime is 81161504761. The reversal of 81161504748 is 84740516118.

81161504748 is a `hidden beast` number, since 8 + 11 + 61 + 504 + 74 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (81161504747) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 49009743 + ... + 49011398.

It is an arithmetic number, because the mean of its divisors is an integer number (5946615948).

Almost surely, 2^81161504748 is an apocalyptic number.

It is an amenable number.

81161504748 is an abundant number, since it is smaller than the sum of its proper divisors (132916669380).

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

81161504748 is a wasteful number, since it uses less digits than its factorization.

81161504748 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98021174 (or 98021169 counting only the distinct ones).

The product of its (nonzero) digits is 215040, while the sum is 45.

The spelling of 81161504748 in words is "eighty-one billion, one hundred sixty-one million, five hundred four thousand, seven hundred forty-eight".