81635238211 has 16 divisors (see below), whose sum is σ = 86449821696. Its totient is φ = 76962600000.

The previous prime is 81635238203. The next prime is 81635238227. The reversal of 81635238211 is 11283253618.

It is a cyclic number.

It is not a de Polignac number, because 81635238211 - 2³ = 81635238203 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81635238241) 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, 831786 + ... + 924736.

It is an arithmetic number, because the mean of its divisors is an integer number (5403113856).

Almost surely, 2^81635238211 is an apocalyptic number.

81635238211 is a deficient number, since it is larger than the sum of its proper divisors (4814583485).

81635238211 is a wasteful number, since it uses less digits than its factorization.

81635238211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93714.

The product of its digits is 69120, while the sum is 40.

The spelling of 81635238211 in words is "eighty-one billion, six hundred thirty-five million, two hundred thirty-eight thousand, two hundred eleven".