81612160000 has 220 divisors, whose sum is σ = 233001953008. Its totient is φ = 27979776000.

The previous prime is 81612159943. The next prime is 81612160001. The reversal of 81612160000 is 6121618.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81612160001) by changing a digit.

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 19 ways as a sum of consecutive naturals, for example, 4470892 + ... + 4489108.

Almost surely, 2^81612160000 is an apocalyptic number.

81612160000 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 81612160000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116500976504).

81612160000 is an abundant number, since it is smaller than the sum of its proper divisors (151389793008).

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

81612160000 is an equidigital number, since it uses as much as digits as its factorization.

81612160000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18264 (or 18231 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 25.

Adding to 81612160000 its reverse (6121618), we get a palindrome (81618281618).

The spelling of 81612160000 in words is "eighty-one billion, six hundred twelve million, one hundred sixty thousand".