81522105174 has 12 divisors (see below), whose sum is σ = 176631227916. Its totient is φ = 27174035052.

The previous prime is 81522105149. The next prime is 81522105179. The reversal of 81522105174 is 47150122518.

It is a happy number.

81522105174 is a `hidden beast` number, since 8 + 1 + 522 + 10 + 51 + 74 = 666.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81522105179) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2264502904 + ... + 2264502939.

It is an arithmetic number, because the mean of its divisors is an integer number (14719268993).

Almost surely, 2^81522105174 is an apocalyptic number.

81522105174 is an abundant number, since it is smaller than the sum of its proper divisors (95109122742).

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

81522105174 is a wasteful number, since it uses less digits than its factorization.

81522105174 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4529005851 (or 4529005848 counting only the distinct ones).

The product of its (nonzero) digits is 22400, while the sum is 36.

The spelling of 81522105174 in words is "eighty-one billion, five hundred twenty-two million, one hundred five thousand, one hundred seventy-four".