81954950237856 has 384 divisors, whose sum is σ = 245935696608000. Its totient is φ = 26540841811968.

The previous prime is 81954950237843. The next prime is 81954950237893. The reversal of 81954950237856 is 65873205945918.

81954950237856 is a `hidden beast` number, since 8 + 1 + 9 + 5 + 4 + 9 + 502 + 37 + 85 + 6 = 666.

It is a super-2 number, since 2×81954950237856² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

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, 16028737956 + ... + 16028743068.

It is an arithmetic number, because the mean of its divisors is an integer number (640457543250).

It is a 1-persistent number, because it is pandigital, but 2⋅81954950237856 = 163909900475712 is not.

Almost surely, 2^{81954950237856} 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 81954950237856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (122967848304000).

81954950237856 is an abundant number, since it is smaller than the sum of its proper divisors (163980746370144).

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

81954950237856 is a wasteful number, since it uses less digits than its factorization.

81954950237856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8813 (or 8799 counting only the distinct ones).

The product of its (nonzero) digits is 653184000, while the sum is 72.

The spelling of 81954950237856 in words is "eighty-one trillion, nine hundred fifty-four billion, nine hundred fifty million, two hundred thirty-seven thousand, eight hundred fifty-six".