81316980064 has 48 divisors (see below), whose sum is σ = 172104307200. Its totient is φ = 37699012224.

The previous prime is 81316980053. The next prime is 81316980089. The reversal of 81316980064 is 46008961318.

It is a super-2 number, since 2×81316980064² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81316979996 and 81316980023.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1394244 + ... + 1451395.

It is an arithmetic number, because the mean of its divisors is an integer number (3585506400).

Almost surely, 2^81316980064 is an apocalyptic number.

It is an amenable number.

81316980064 is an abundant number, since it is smaller than the sum of its proper divisors (90787327136).

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

81316980064 is a wasteful number, since it uses less digits than its factorization.

81316980064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2845715 (or 2845707 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 46.

The spelling of 81316980064 in words is "eighty-one billion, three hundred sixteen million, nine hundred eighty thousand, sixty-four".