81878745198 has 64 divisors (see below), whose sum is σ = 175420627200. Its totient is φ = 25403258880.

The previous prime is 81878745187. The next prime is 81878745199. The reversal of 81878745198 is 89154787818.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81878745199) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1688718 + ... + 1736526.

It is an arithmetic number, because the mean of its divisors is an integer number (2740947300).

Almost surely, 2^81878745198 is an apocalyptic number.

81878745198 is an abundant number, since it is smaller than the sum of its proper divisors (93541882002).

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

81878745198 is a wasteful number, since it uses less digits than its factorization.

81878745198 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48097.

The product of its digits is 36126720, while the sum is 66.

The spelling of 81878745198 in words is "eighty-one billion, eight hundred seventy-eight million, seven hundred forty-five thousand, one hundred ninety-eight".