81641059019 has 16 divisors (see below), whose sum is σ = 90789264384. Its totient is φ = 72904298400.

The previous prime is 81641059013. The next prime is 81641059067. The reversal of 81641059019 is 91095014618.

It is a cyclic number.

It is not a de Polignac number, because 81641059019 - 2²⁰ = 81640010443 is a prime.

It is a super-2 number, since 2×81641059019² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81641059013) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1159904 + ... + 1228274.

It is an arithmetic number, because the mean of its divisors is an integer number (5674329024).

Almost surely, 2^81641059019 is an apocalyptic number.

81641059019 is a deficient number, since it is larger than the sum of its proper divisors (9148205365).

81641059019 is a wasteful number, since it uses less digits than its factorization.

81641059019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71378.

The product of its (nonzero) digits is 77760, while the sum is 44.

The spelling of 81641059019 in words is "eighty-one billion, six hundred forty-one million, fifty-nine thousand, nineteen".