81080442943645 has 32 divisors (see below), whose sum is σ = 99115463116800. Its totient is φ = 63655594998336.

The previous prime is 81080442943603. The next prime is 81080442943649. The reversal of 81080442943645 is 54634924408018.

It is a cyclic number.

It is not a de Polignac number, because 81080442943645 - 2²⁹ = 81079906072733 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81080442943645.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81080442943649) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 435572682 + ... + 435758788.

It is an arithmetic number, because the mean of its divisors is an integer number (3097358222400).

Almost surely, 2^{81080442943645} is an apocalyptic number.

It is an amenable number.

81080442943645 is a deficient number, since it is larger than the sum of its proper divisors (18035020173155).

81080442943645 is a wasteful number, since it uses less digits than its factorization.

81080442943645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188697.

The product of its (nonzero) digits is 26542080, while the sum is 58.

The spelling of 81080442943645 in words is "eighty-one trillion, eighty billion, four hundred forty-two million, nine hundred forty-three thousand, six hundred forty-five".