81821112700 has 18 divisors (see below), whose sum is σ = 177551814776. Its totient is φ = 32728445040.

The previous prime is 81821112689. The next prime is 81821112713. The reversal of 81821112700 is 721112818.

It is a super-2 number, since 2×81821112700² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 409105464 + ... + 409105663.

Almost surely, 2^81821112700 is an apocalyptic number.

It is an amenable number.

81821112700 is an abundant number, since it is smaller than the sum of its proper divisors (95730702076).

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

81821112700 is a wasteful number, since it uses less digits than its factorization.

81821112700 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 818211141 (or 818211134 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 31.

The spelling of 81821112700 in words is "eighty-one billion, eight hundred twenty-one million, one hundred twelve thousand, seven hundred".