81641452940356 has 9 divisors (see below), whose sum is σ = 142872574270111. Its totient is φ = 40820717434612.

The previous prime is 81641452940279. The next prime is 81641452940381. The reversal of 81641452940356 is 65304925414618.

The square root of 81641452940356 is 9035566.

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

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81641452940356.

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 2 ways as a sum of consecutive naturals, for example, 15812241 + ... + 20330023.

Almost surely, 2^{81641452940356} is an apocalyptic number.

81641452940356 is the 9035566-th square number.

It is an amenable number.

81641452940356 is a deficient number, since it is larger than the sum of its proper divisors (61231121329755).

81641452940356 is an frugal number, since it uses more digits than its factorization.

81641452940356 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9035570 (or 4517785 counting only the distinct ones).

The product of its (nonzero) digits is 24883200, while the sum is 58.

The spelling of 81641452940356 in words is "eighty-one trillion, six hundred forty-one billion, four hundred fifty-two million, nine hundred forty thousand, three hundred fifty-six".