81368133000 has 512 divisors, whose sum is σ = 318600622080. Its totient is φ = 16796160000.

The previous prime is 81368132983. The next prime is 81368133013. The reversal of 81368133000 is 33186318.

It is a happy number.

It is a Cunningham number, because it is equal to 285251²-1.

It is a Harshad number since it is a multiple of its sum of digits (33).

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 127 ways as a sum of consecutive naturals, for example, 37651920 + ... + 37654080.

It is an arithmetic number, because the mean of its divisors is an integer number (622266840).

Almost surely, 2^81368133000 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 81368133000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (159300311040).

81368133000 is an abundant number, since it is smaller than the sum of its proper divisors (237232489080).

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

81368133000 is a wasteful number, since it uses less digits than its factorization.

81368133000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2366 (or 2352 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The spelling of 81368133000 in words is "eighty-one billion, three hundred sixty-eight million, one hundred thirty-three thousand".