81272899290686 has 16 divisors (see below), whose sum is σ = 121936775773824. Its totient is φ = 40627307742624.

The previous prime is 81272899290683. The next prime is 81272899290697. The reversal of 81272899290686 is 68609299827218.

It is a super-2 number, since 2×81272899290686² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81272899290683) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 777358931 + ... + 777463473.

It is an arithmetic number, because the mean of its divisors is an integer number (7621048485864).

Almost surely, 2^{81272899290686} is an apocalyptic number.

81272899290686 is a deficient number, since it is larger than the sum of its proper divisors (40663876483138).

81272899290686 is a wasteful number, since it uses less digits than its factorization.

81272899290686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188275.

The product of its (nonzero) digits is 752467968, while the sum is 77.

The spelling of 81272899290686 in words is "eighty-one trillion, two hundred seventy-two billion, eight hundred ninety-nine million, two hundred ninety thousand, six hundred eighty-six".