81635873100 has 72 divisors (see below), whose sum is σ = 248631378240. Its totient is φ = 20623798080.

The previous prime is 81635873069. The next prime is 81635873107. The reversal of 81635873100 is 137853618.

It is a super-2 number, since 2×81635873100² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81635873107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7155342 + ... + 7166741.

Almost surely, 2^81635873100 is an apocalyptic number.

It is an amenable number.

81635873100 is an abundant number, since it is smaller than the sum of its proper divisors (166995505140).

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

81635873100 is a wasteful number, since it uses less digits than its factorization.

81635873100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14322119 (or 14322112 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 42.

The spelling of 81635873100 in words is "eighty-one billion, six hundred thirty-five million, eight hundred seventy-three thousand, one hundred".