81698180100 has 144 divisors (see below), whose sum is σ = 250727577408. Its totient is φ = 20468367360.

The previous prime is 81698180087. The next prime is 81698180107. The reversal of 81698180100 is 108189618.

It is not an unprimeable number, because it can be changed into a prime (81698180107) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2928819 + ... + 2956581.

It is an arithmetic number, because the mean of its divisors is an integer number (1741163732).

Almost surely, 2^81698180100 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81698180100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (125363788704).

81698180100 is an abundant number, since it is smaller than the sum of its proper divisors (169029397308).

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

81698180100 is a wasteful number, since it uses less digits than its factorization.

81698180100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28374 (or 28367 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 42.

The spelling of 81698180100 in words is "eighty-one billion, six hundred ninety-eight million, one hundred eighty thousand, one hundred".