81144612000 has 768 divisors, whose sum is σ = 306992125440. Its totient is φ = 20805120000.

The previous prime is 81144611983. The next prime is 81144612011. The reversal of 81144612000 is 21644118.

It is a happy number.

81144612000 is a `hidden beast` number, since 8 + 1 + 1 + 44 + 612 + 0 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 469043914 + ... + 469044086.

It is an arithmetic number, because the mean of its divisors is an integer number (399729330).

Almost surely, 2^81144612000 is an apocalyptic number.

81144612000 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81144612000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (153496062720).

81144612000 is an abundant number, since it is smaller than the sum of its proper divisors (225847513440).

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

81144612000 is a wasteful number, since it uses less digits than its factorization.

81144612000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 351 (or 327 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The spelling of 81144612000 in words is "eighty-one billion, one hundred forty-four million, six hundred twelve thousand".