81340038049920 has 512 divisors, whose sum is σ = 284110338274560. Its totient is φ = 19671883776000.

The previous prime is 81340038049883. The next prime is 81340038049951. The reversal of 81340038049920 is 2994083004318.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1380932470 + ... + 1380991370.

Almost surely, 2^{81340038049920} is an apocalyptic number.

81340038049920 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 81340038049920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (142055169137280).

81340038049920 is an abundant number, since it is smaller than the sum of its proper divisors (202770300224640).

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

81340038049920 is a wasteful number, since it uses less digits than its factorization.

81340038049920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59904 (or 59892 counting only the distinct ones).

The product of its (nonzero) digits is 1492992, while the sum is 51.

The spelling of 81340038049920 in words is "eighty-one trillion, three hundred forty billion, thirty-eight million, forty-nine thousand, nine hundred twenty".