81355467317 has 4 divisors (see below), whose sum is σ = 81497946816. Its totient is φ = 81212987820.

The previous prime is 81355467311. The next prime is 81355467371. The reversal of 81355467317 is 71376455318.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81355467317 - 2¹⁶ = 81355401781 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81355467311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71238893 + ... + 71240034.

It is an arithmetic number, because the mean of its divisors is an integer number (20374486704).

Almost surely, 2^81355467317 is an apocalyptic number.

It is an amenable number.

81355467317 is a deficient number, since it is larger than the sum of its proper divisors (142479499).

81355467317 is a wasteful number, since it uses less digits than its factorization.

81355467317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142479498.

The product of its digits is 2116800, while the sum is 50.

The spelling of 81355467317 in words is "eighty-one billion, three hundred fifty-five million, four hundred sixty-seven thousand, three hundred seventeen".