81812896400 has 30 divisors (see below), whose sum is σ = 196555484562. Its totient is φ = 32725158400.

The previous prime is 81812896397. The next prime is 81812896433. The reversal of 81812896400 is 469821818.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 14704957696 + 67107938704 = 121264^2 + 259052^2 .

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 5 ways as a sum of consecutive naturals, for example, 102265721 + ... + 102266520.

Almost surely, 2^81812896400 is an apocalyptic number.

81812896400 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81812896400 is an abundant number, since it is smaller than the sum of its proper divisors (114742588162).

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

81812896400 is a wasteful number, since it uses less digits than its factorization.

81812896400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204532259 (or 204532248 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 47.

The spelling of 81812896400 in words is "eighty-one billion, eight hundred twelve million, eight hundred ninety-six thousand, four hundred".