81956943111 has 8 divisors (see below), whose sum is σ = 109341483264. Its totient is φ = 54605182520.

The previous prime is 81956943077. The next prime is 81956943127. The reversal of 81956943111 is 11134965918.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81956943111 - 2¹¹ = 81956941063 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81956943161) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8189055 + ... + 8199056.

It is an arithmetic number, because the mean of its divisors is an integer number (13667685408).

Almost surely, 2^81956943111 is an apocalyptic number.

81956943111 is a deficient number, since it is larger than the sum of its proper divisors (27384540153).

81956943111 is a wasteful number, since it uses less digits than its factorization.

81956943111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16389781.

The product of its digits is 233280, while the sum is 48.

The spelling of 81956943111 in words is "eighty-one billion, nine hundred fifty-six million, nine hundred forty-three thousand, one hundred eleven".