81943025187 has 16 divisors (see below), whose sum is σ = 111672433152. Its totient is φ = 53423034720.

The previous prime is 81943025179. The next prime is 81943025231. The reversal of 81943025187 is 78152034918.

It is not a de Polignac number, because 81943025187 - 2³ = 81943025179 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81943025107) 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 15 ways as a sum of consecutive naturals, for example, 60489 + ... + 409322.

It is an arithmetic number, because the mean of its divisors is an integer number (6979527072).

Almost surely, 2^81943025187 is an apocalyptic number.

81943025187 is a deficient number, since it is larger than the sum of its proper divisors (29729407965).

81943025187 is a wasteful number, since it uses less digits than its factorization.

81943025187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 471098.

The product of its (nonzero) digits is 483840, while the sum is 48.

The spelling of 81943025187 in words is "eighty-one billion, nine hundred forty-three million, twenty-five thousand, one hundred eighty-seven".