81920340198 has 32 divisors (see below), whose sum is σ = 186485332320. Its totient is φ = 26640760320.

The previous prime is 81920340143. The next prime is 81920340211. The reversal of 81920340198 is 89104302918.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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, 18498315 + ... + 18502742.

It is an arithmetic number, because the mean of its divisors is an integer number (5827666635).

Almost surely, 2^81920340198 is an apocalyptic number.

81920340198 is an abundant number, since it is smaller than the sum of its proper divisors (104564992122).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81920340198 is a wasteful number, since it uses less digits than its factorization.

81920340198 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37001109 (or 37001103 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 45.

The spelling of 81920340198 in words is "eighty-one billion, nine hundred twenty million, three hundred forty thousand, one hundred ninety-eight".