81698104042 has 16 divisors (see below), whose sum is σ = 133262728200. Its totient is φ = 37407080448.

The previous prime is 81698104021. The next prime is 81698104043. The reversal of 81698104042 is 24040189618.

It can be written as a sum of positive squares in 4 ways, for example, as 80786124441 + 911979601 = 284229^2 + 30199^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 81698104042.

It is not an unprimeable number, because it can be changed into a prime (81698104043) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32470167 + ... + 32472682.

Almost surely, 2^81698104042 is an apocalyptic number.

81698104042 is a deficient number, since it is larger than the sum of its proper divisors (51564624158).

81698104042 is a wasteful number, since it uses less digits than its factorization.

81698104042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64942905.

The product of its (nonzero) digits is 110592, while the sum is 43.

The spelling of 81698104042 in words is "eighty-one billion, six hundred ninety-eight million, one hundred four thousand, forty-two".