81373612253265 has 24 divisors (see below), whose sum is σ = 141069224830248. Its totient is φ = 43392604404480.

The previous prime is 81373612253237. The next prime is 81373612253273. The reversal of 81373612253265 is 56235221637318.

81373612253265 is a `hidden beast` number, since 8 + 1 + 3 + 7 + 36 + 12 + 2 + 532 + 65 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 24114002181201 + 57259610072064 = 4910601^2 + 7567008^2 .

It is not a de Polignac number, because 81373612253265 - 2⁷ = 81373612253137 is a prime.

It is a super-2 number, since 2×81373612253265² (a number of 29 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 138358794 + ... + 138945683.

It is an arithmetic number, because the mean of its divisors is an integer number (5877884367927).

Almost surely, 2^{81373612253265} is an apocalyptic number.

It is an amenable number.

81373612253265 is a deficient number, since it is larger than the sum of its proper divisors (59695612576983).

81373612253265 is a wasteful number, since it uses less digits than its factorization.

81373612253265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 277311009 (or 277311006 counting only the distinct ones).

The product of its digits is 10886400, while the sum is 54.

The spelling of 81373612253265 in words is "eighty-one trillion, three hundred seventy-three billion, six hundred twelve million, two hundred fifty-three thousand, two hundred sixty-five".