81267996600 has 288 divisors, whose sum is σ = 323468046720. Its totient is φ = 18575464320.

The previous prime is 81267996581. The next prime is 81267996653. The reversal of 81267996600 is 669976218.

81267996600 is a `hidden beast` number, since 8 + 1 + 26 + 7 + 9 + 9 + 6 + 600 = 666.

It is a super-2 number, since 2×81267996600² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 220759 + ... + 459641.

It is an arithmetic number, because the mean of its divisors is an integer number (1123152940).

Almost surely, 2^81267996600 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 81267996600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (161734023360).

81267996600 is an abundant number, since it is smaller than the sum of its proper divisors (242200050120).

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

81267996600 is a wasteful number, since it uses less digits than its factorization.

81267996600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 238921 (or 238900 counting only the distinct ones).

The product of its (nonzero) digits is 1959552, while the sum is 54.

The spelling of 81267996600 in words is "eighty-one billion, two hundred sixty-seven million, nine hundred ninety-six thousand, six hundred".