81337161600000 has 396 divisors, whose sum is σ = 293555426437728. Its totient is φ = 21689902080000.

The previous prime is 81337161599977. The next prime is 81337161600011. The reversal of 81337161600000 is 616173318.

81337161600000 is a `hidden beast` number, since 8 + 1 + 3 + 37 + 1 + 616 + 0 + 0 + 0 + 0 + 0 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 27387897 + ... + 30212103.

Almost surely, 2^{81337161600000} is an apocalyptic number.

81337161600000 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 81337161600000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (146777713218864).

81337161600000 is an abundant number, since it is smaller than the sum of its proper divisors (212218264837728).

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

81337161600000 is an equidigital number, since it uses as much as digits as its factorization.

81337161600000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2824258 (or 2824217 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

Adding to 81337161600000 its reverse (616173318), we get a palindrome (81337777773318).

The spelling of 81337161600000 in words is "eighty-one trillion, three hundred thirty-seven billion, one hundred sixty-one million, six hundred thousand".