81244523547 has 24 divisors (see below), whose sum is σ = 133587836928. Its totient is φ = 47098273200.

The previous prime is 81244523483. The next prime is 81244523561. The reversal of 81244523547 is 74532544218.

81244523547 is a `hidden beast` number, since 8 + 1 + 244 + 52 + 354 + 7 = 666.

It is not a de Polignac number, because 81244523547 - 2⁶ = 81244523483 is a prime.

It is a super-2 number, since 2×81244523547² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81244523587) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17837979 + ... + 17842532.

It is an arithmetic number, because the mean of its divisors is an integer number (5566159872).

Almost surely, 2^81244523547 is an apocalyptic number.

81244523547 is a deficient number, since it is larger than the sum of its proper divisors (52343313381).

81244523547 is a wasteful number, since it uses less digits than its factorization.

81244523547 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35680551 (or 35680548 counting only the distinct ones).

The product of its digits is 1075200, while the sum is 45.

The spelling of 81244523547 in words is "eighty-one billion, two hundred forty-four million, five hundred twenty-three thousand, five hundred forty-seven".