81514818064 has 45 divisors (see below), whose sum is σ = 159402137671. Its totient is φ = 40382251520.

The previous prime is 81514818031. The next prime is 81514818127. The reversal of 81514818064 is 46081841518.

The square root of 81514818064 is 285508.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 1421290000 + 80093528064 = 37700^2 + 283008^2 .

It is a Smith number, since the sum of its digits (46) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 156458124 + ... + 156458644.

Almost surely, 2^81514818064 is an apocalyptic number.

81514818064 is the 285508-th square number.

It is an amenable number.

81514818064 is a deficient number, since it is larger than the sum of its proper divisors (77887319607).

81514818064 is an frugal number, since it uses more digits than its factorization.

81514818064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1324 (or 660 counting only the distinct ones).

The product of its (nonzero) digits is 245760, while the sum is 46.

The spelling of 81514818064 in words is "eighty-one billion, five hundred fourteen million, eight hundred eighteen thousand, sixty-four".