81368100 has 108 divisors (see below), whose sum is σ = 278263440. Its totient is φ = 19723200.

The previous prime is 81368047. The next prime is 81368117. The reversal of 81368100 is 186318.

It is a super-2 number, since 2×81368100² = 13241535395220000, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 5791 + ... + 14009.

Almost surely, 2^81368100 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 81368100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (139131720).

81368100 is an abundant number, since it is smaller than the sum of its proper divisors (196895340).

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

81368100 is a wasteful number, since it uses less digits than its factorization.

81368100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8250 (or 8240 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 81368100 is about 9020.4268191699. The cubic root of 81368100 is about 433.3293030526.

The spelling of 81368100 in words is "eighty-one million, three hundred sixty-eight thousand, one hundred".