81802864144 has 15 divisors (see below), whose sum is σ = 158495265903. Its totient is φ = 40900860048.

The previous prime is 81802864079. The next prime is 81802864153. The reversal of 81802864144 is 44146820818.

The square root of 81802864144 is 286012.

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

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81802864094 and 81802864103.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 1108297 + ... + 1179799.

Almost surely, 2^81802864144 is an apocalyptic number.

81802864144 is the 286012-nd square number.

It is an amenable number.

81802864144 is a deficient number, since it is larger than the sum of its proper divisors (76692401759).

81802864144 is an frugal number, since it uses more digits than its factorization.

81802864144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143014 (or 71505 counting only the distinct ones).

The product of its (nonzero) digits is 393216, while the sum is 46.

The spelling of 81802864144 in words is "eighty-one billion, eight hundred two million, eight hundred sixty-four thousand, one hundred forty-four".