81173047284 has 144 divisors (see below), whose sum is σ = 243467952000. Its totient is φ = 22311168768.

The previous prime is 81173047231. The next prime is 81173047289. The reversal of 81173047284 is 48274037118.

81173047284 is a `hidden beast` number, since 8 + 1 + 173 + 0 + 472 + 8 + 4 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81173047289) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2004267 + ... + 2044365.

Almost surely, 2^81173047284 is an apocalyptic number.

81173047284 is a gapful number since it is divisible by the number (84) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81173047284, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (121733976000).

81173047284 is an abundant number, since it is smaller than the sum of its proper divisors (162294904716).

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

81173047284 is a wasteful number, since it uses less digits than its factorization.

81173047284 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40422 (or 40417 counting only the distinct ones).

The product of its (nonzero) digits is 301056, while the sum is 45.

The spelling of 81173047284 in words is "eighty-one billion, one hundred seventy-three million, forty-seven thousand, two hundred eighty-four".