81041813405 has 32 divisors (see below), whose sum is σ = 114623545344. Its totient is φ = 53851646016.

The previous prime is 81041813389. The next prime is 81041813429. The reversal of 81041813405 is 50431814018.

It is not a de Polignac number, because 81041813405 - 2⁴ = 81041813389 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20867 + ... + 403136.

It is an arithmetic number, because the mean of its divisors is an integer number (3581985792).

Almost surely, 2^81041813405 is an apocalyptic number.

It is an amenable number.

81041813405 is a deficient number, since it is larger than the sum of its proper divisors (33581731939).

81041813405 is a wasteful number, since it uses less digits than its factorization.

81041813405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 424185.

The product of its (nonzero) digits is 15360, while the sum is 35.

The spelling of 81041813405 in words is "eighty-one billion, forty-one million, eight hundred thirteen thousand, four hundred five".