81975890324 has 12 divisors (see below), whose sum is σ = 143469689748. Its totient is φ = 40984550400.

The previous prime is 81975890309. The next prime is 81975890327. The reversal of 81975890324 is 42309857918.

It can be written as a sum of positive squares in 2 ways, for example, as 20486769424 + 61489120900 = 143132^2 + 247970^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 81975890324.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81975890327) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 793967 + ... + 891254.

It is an arithmetic number, because the mean of its divisors is an integer number (11955807479).

Almost surely, 2^81975890324 is an apocalyptic number.

It is an amenable number.

81975890324 is a deficient number, since it is larger than the sum of its proper divisors (61493799424).

81975890324 is a wasteful number, since it uses less digits than its factorization.

81975890324 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1697386 (or 1697384 counting only the distinct ones).

The product of its (nonzero) digits is 4354560, while the sum is 56.

The spelling of 81975890324 in words is "eighty-one billion, nine hundred seventy-five million, eight hundred ninety thousand, three hundred twenty-four".