81442863695 has 4 divisors (see below), whose sum is σ = 97731436440. Its totient is φ = 65154290952.

The previous prime is 81442863653. The next prime is 81442863701. The reversal of 81442863695 is 59636824418.

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 81442863695 - 2¹⁸ = 81442601551 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81442863695.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8144286365 + ... + 8144286374.

It is an arithmetic number, because the mean of its divisors is an integer number (24432859110).

Almost surely, 2^81442863695 is an apocalyptic number.

81442863695 is a deficient number, since it is larger than the sum of its proper divisors (16288572745).

81442863695 is a wasteful number, since it uses less digits than its factorization.

81442863695 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16288572744.

The product of its digits is 9953280, while the sum is 56.

The spelling of 81442863695 in words is "eighty-one billion, four hundred forty-two million, eight hundred sixty-three thousand, six hundred ninety-five".