81767800 has 48 divisors (see below), whose sum is σ = 190780200. Its totient is φ = 32592000.

The previous prime is 81767797. The next prime is 81767813. The reversal of 81767800 is 876718.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 81767800.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 77275 + ... + 78325.

Almost surely, 2^81767800 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 81767800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95390100).

81767800 is an abundant number, since it is smaller than the sum of its proper divisors (109012400).

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

81767800 is a wasteful number, since it uses less digits than its factorization.

81767800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1456 (or 1447 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 37.

The square root of 81767800 is about 9042.5549486857. The cubic root of 81767800 is about 434.0376842273.

The spelling of 81767800 in words is "eighty-one million, seven hundred sixty-seven thousand, eight hundred".