81440162323 has 4 divisors (see below), whose sum is σ = 87704790208. Its totient is φ = 75175534440.

The previous prime is 81440162303. The next prime is 81440162339. The reversal of 81440162323 is 32326104418.

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 81440162323 - 2⁹ = 81440161811 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81440162303) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3132313923 + ... + 3132313948.

It is an arithmetic number, because the mean of its divisors is an integer number (21926197552).

Almost surely, 2^81440162323 is an apocalyptic number.

81440162323 is a deficient number, since it is larger than the sum of its proper divisors (6264627885).

81440162323 is a wasteful number, since it uses less digits than its factorization.

81440162323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6264627884.

The product of its (nonzero) digits is 27648, while the sum is 34.

The spelling of 81440162323 in words is "eighty-one billion, four hundred forty million, one hundred sixty-two thousand, three hundred twenty-three".