81776131800 has 576 divisors, whose sum is σ = 289755204480. Its totient is φ = 19050240000.

The previous prime is 81776131739. The next prime is 81776131819. The reversal of 81776131800 is 813167718.

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 143 ways as a sum of consecutive naturals, for example, 247057635 + ... + 247057965.

It is an arithmetic number, because the mean of its divisors is an integer number (503047230).

Almost surely, 2^81776131800 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 81776131800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (144877602240).

81776131800 is an abundant number, since it is smaller than the sum of its proper divisors (207979072680).

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

81776131800 is a wasteful number, since it uses less digits than its factorization.

81776131800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 496 (or 476 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 42.

The spelling of 81776131800 in words is "eighty-one billion, seven hundred seventy-six million, one hundred thirty-one thousand, eight hundred".