181311791136 has 96 divisors (see below), whose sum is σ = 561481740288. Its totient is φ = 50132286720.

The previous prime is 181311791069. The next prime is 181311791137. The reversal of 181311791136 is 631197113181.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (181311791137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4330930 + ... + 4372593.

It is an arithmetic number, because the mean of its divisors is an integer number (5848768128).

Almost surely, 2^181311791136 is an apocalyptic number.

181311791136 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

181311791136 is an abundant number, since it is smaller than the sum of its proper divisors (380169949152).

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

181311791136 is a wasteful number, since it uses less digits than its factorization.

181311791136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8703574 (or 8703566 counting only the distinct ones).

The product of its digits is 27216, while the sum is 42.

The spelling of 181311791136 in words is "one hundred eighty-one billion, three hundred eleven million, seven hundred ninety-one thousand, one hundred thirty-six".