81268531200000 has 2448 divisors, whose sum is σ = 322020836347392. Its totient is φ = 20437401600000.

The previous prime is 81268531199987. The next prime is 81268531200007. The reversal of 81268531200000 is 213586218.

It is a happy number.

81268531200000 is a `hidden beast` number, since 81 + 26 + 8 + 531 + 20 + 0 + 0 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81268531200007) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 1144627199965 + ... + 1144627200035.

Almost surely, 2^{81268531200000} is an apocalyptic number.

81268531200000 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 81268531200000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (161010418173696).

81268531200000 is an abundant number, since it is smaller than the sum of its proper divisors (240752305147392).

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

81268531200000 is an frugal number, since it uses more digits than its factorization.

81268531200000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166 (or 104 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

Adding to 81268531200000 its reverse (213586218), we get a palindrome (81268744786218).

The spelling of 81268531200000 in words is "eighty-one trillion, two hundred sixty-eight billion, five hundred thirty-one million, two hundred thousand".