81699876180 has 144 divisors (see below), whose sum is σ = 275233815360. Its totient is φ = 20110716288.

The previous prime is 81699876079. The next prime is 81699876197. The reversal of 81699876180 is 8167899618.

81699876180 is a `hidden beast` number, since 8 + 1 + 6 + 9 + 9 + 8 + 7 + 618 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 356362 + ... + 538881.

It is an arithmetic number, because the mean of its divisors is an integer number (1911345940).

Almost surely, 2^81699876180 is an apocalyptic number.

It is an amenable number.

81699876180 is an abundant number, since it is smaller than the sum of its proper divisors (193533939180).

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

81699876180 is a wasteful number, since it uses less digits than its factorization.

81699876180 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 895287 (or 895266 counting only the distinct ones).

The product of its (nonzero) digits is 10450944, while the sum is 63.

The spelling of 81699876180 in words is "eighty-one billion, six hundred ninety-nine million, eight hundred seventy-six thousand, one hundred eighty".