81742522172 has 12 divisors (see below), whose sum is σ = 146915614440. Its totient is φ = 39766632336.

The previous prime is 81742522163. The next prime is 81742522177. The reversal of 81742522172 is 27122524718.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81742522177) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 276157022 + ... + 276157317.

It is an arithmetic number, because the mean of its divisors is an integer number (12242967870).

Almost surely, 2^81742522172 is an apocalyptic number.

It is an amenable number.

81742522172 is a deficient number, since it is larger than the sum of its proper divisors (65173092268).

81742522172 is a wasteful number, since it uses less digits than its factorization.

81742522172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 552314380 (or 552314378 counting only the distinct ones).

The product of its digits is 125440, while the sum is 41.

The spelling of 81742522172 in words is "eighty-one billion, seven hundred forty-two million, five hundred twenty-two thousand, one hundred seventy-two".