81272371247 has 4 divisors (see below), whose sum is σ = 82301135520. Its totient is φ = 80243606976.

The previous prime is 81272371241. The next prime is 81272371259. The reversal of 81272371247 is 74217327218.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81272371247 - 2⁴ = 81272371231 is a prime.

It is a super-2 number, since 2×81272371247² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81272371198 and 81272371207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81272371241) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 514382018 + ... + 514382175.

It is an arithmetic number, because the mean of its divisors is an integer number (20575283880).

Almost surely, 2^81272371247 is an apocalyptic number.

81272371247 is a deficient number, since it is larger than the sum of its proper divisors (1028764273).

81272371247 is a wasteful number, since it uses less digits than its factorization.

81272371247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1028764272.

The product of its digits is 263424, while the sum is 44.

The spelling of 81272371247 in words is "eighty-one billion, two hundred seventy-two million, three hundred seventy-one thousand, two hundred forty-seven".