81541723371 has 16 divisors (see below), whose sum is σ = 116411191200. Its totient is φ = 50588561408.

The previous prime is 81541723309. The next prime is 81541723381. The reversal of 81541723371 is 17332714518.

It is a cyclic number.

It is not a de Polignac number, because 81541723371 - 2⁷ = 81541723243 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81541723381) 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, 8977806 + ... + 8986883.

It is an arithmetic number, because the mean of its divisors is an integer number (7275699450).

Almost surely, 2^81541723371 is an apocalyptic number.

81541723371 is a deficient number, since it is larger than the sum of its proper divisors (34869467829).

81541723371 is a wasteful number, since it uses less digits than its factorization.

81541723371 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17964798.

The product of its digits is 141120, while the sum is 42.

The spelling of 81541723371 in words is "eighty-one billion, five hundred forty-one million, seven hundred twenty-three thousand, three hundred seventy-one".