81940101616128 has 320 divisors, whose sum is σ = 256335733463040. Its totient is φ = 22771401523200.

The previous prime is 81940101616069. The next prime is 81940101616147. The reversal of 81940101616128 is 82161610104918.

It is a super-2 number, since 2×81940101616128² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 145634613 + ... + 146196171.

It is an arithmetic number, because the mean of its divisors is an integer number (801049167072).

Almost surely, 2^{81940101616128} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81940101616128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128167866731520).

81940101616128 is an abundant number, since it is smaller than the sum of its proper divisors (174395631846912).

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

81940101616128 is a wasteful number, since it uses less digits than its factorization.

81940101616128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 561959 (or 561943 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 48.

The spelling of 81940101616128 in words is "eighty-one trillion, nine hundred forty billion, one hundred one million, six hundred sixteen thousand, one hundred twenty-eight".