81940305835 has 4 divisors (see below), whose sum is σ = 98328367008. Its totient is φ = 65552244664.

The previous prime is 81940305833. The next prime is 81940305851. The reversal of 81940305835 is 53850304918.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81940305835 - 2¹ = 81940305833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81940305833) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8194030579 + ... + 8194030588.

It is an arithmetic number, because the mean of its divisors is an integer number (24582091752).

Almost surely, 2^81940305835 is an apocalyptic number.

81940305835 is a deficient number, since it is larger than the sum of its proper divisors (16388061173).

81940305835 is a wasteful number, since it uses less digits than its factorization.

81940305835 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16388061172.

The product of its (nonzero) digits is 518400, while the sum is 46.

The spelling of 81940305835 in words is "eighty-one billion, nine hundred forty million, three hundred five thousand, eight hundred thirty-five".