81450931643 has 8 divisors (see below), whose sum is σ = 83006998128. Its totient is φ = 79895578464.

The previous prime is 81450931591. The next prime is 81450931673. The reversal of 81450931643 is 34613905418.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81450931643 - 2²⁴ = 81434154427 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81450931594 and 81450931603.

It is not an unprimeable number, because it can be changed into a prime (81450931673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55121 + ... + 407357.

It is an arithmetic number, because the mean of its divisors is an integer number (10375874766).

Almost surely, 2^81450931643 is an apocalyptic number.

81450931643 is a deficient number, since it is larger than the sum of its proper divisors (1556066485).

81450931643 is a wasteful number, since it uses less digits than its factorization.

81450931643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 356653.

The product of its (nonzero) digits is 311040, while the sum is 44.

The spelling of 81450931643 in words is "eighty-one billion, four hundred fifty million, nine hundred thirty-one thousand, six hundred forty-three".