81950489693 has 8 divisors (see below), whose sum is σ = 82072773120. Its totient is φ = 81828280080.

The previous prime is 81950489681. The next prime is 81950489743. The reversal of 81950489693 is 39698405918.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81950489693 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81950489623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2443508 + ... + 2476818.

It is an arithmetic number, because the mean of its divisors is an integer number (10259096640).

Almost surely, 2^81950489693 is an apocalyptic number.

It is an amenable number.

81950489693 is a deficient number, since it is larger than the sum of its proper divisors (122283427).

81950489693 is a wasteful number, since it uses less digits than its factorization.

81950489693 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36907.

The product of its (nonzero) digits is 16796160, while the sum is 62.

The spelling of 81950489693 in words is "eighty-one billion, nine hundred fifty million, four hundred eighty-nine thousand, six hundred ninety-three".