81694897975 has 6 divisors (see below), whose sum is σ = 101301673520. Its totient is φ = 65355918360.

The previous prime is 81694897969. The next prime is 81694897979. The reversal of 81694897975 is 57979849618.

It is not a de Polignac number, because 81694897975 - 2¹⁵ = 81694865207 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81694897898 and 81694897907.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81694897979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1633897935 + ... + 1633897984.

Almost surely, 2^81694897975 is an apocalyptic number.

81694897975 is a deficient number, since it is larger than the sum of its proper divisors (19606775545).

81694897975 is a wasteful number, since it uses less digits than its factorization.

81694897975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3267795929 (or 3267795924 counting only the distinct ones).

The product of its digits is 274337280, while the sum is 73.

The spelling of 81694897975 in words is "eighty-one billion, six hundred ninety-four million, eight hundred ninety-seven thousand, nine hundred seventy-five".