81648084690 has 48 divisors (see below), whose sum is σ = 214670266200. Its totient is φ = 21528182016.

The previous prime is 81648084689. The next prime is 81648084691. The reversal of 81648084690 is 9648084618.

81648084690 is a `hidden beast` number, since 81 + 6 + 480 + 84 + 6 + 9 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (81648084689) and next prime (81648084691).

It can be written as a sum of positive squares in 4 ways, for example, as 48083279841 + 33564804849 = 219279^2 + 183207^2 .

It is a super-2 number, since 2×81648084690² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81648084691) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 5088625 + ... + 5104644.

Almost surely, 2^81648084690 is an apocalyptic number.

81648084690 is an abundant number, since it is smaller than the sum of its proper divisors (133022181510).

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

81648084690 is a wasteful number, since it uses less digits than its factorization.

81648084690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10193371 (or 10193368 counting only the distinct ones).

The product of its (nonzero) digits is 2654208, while the sum is 54.

The spelling of 81648084690 in words is "eighty-one billion, six hundred forty-eight million, eighty-four thousand, six hundred ninety".