81939675063 has 8 divisors (see below), whose sum is σ = 115003052800. Its totient is φ = 51751373688.

The previous prime is 81939675061. The next prime is 81939675071. The reversal of 81939675063 is 36057693918.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81939675063 - 2¹ = 81939675061 is a prime.

It is a super-2 number, since 2×81939675063² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (57), and also a Moran number because the ratio is a prime number: 1437538159 = 81939675063 / (8 + 1 + 9 + 3 + 9 + 6 + 7 + 5 + 0 + 6 + 3).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81939674994 and 81939675012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81939675061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 718769023 + ... + 718769136.

It is an arithmetic number, because the mean of its divisors is an integer number (14375381600).

Almost surely, 2^81939675063 is an apocalyptic number.

81939675063 is a deficient number, since it is larger than the sum of its proper divisors (33063377737).

81939675063 is a wasteful number, since it uses less digits than its factorization.

81939675063 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1437538181.

The product of its (nonzero) digits is 7348320, while the sum is 57.

The spelling of 81939675063 in words is "eighty-one billion, nine hundred thirty-nine million, six hundred seventy-five thousand, sixty-three".