81352181971353 has 4 divisors (see below), whose sum is σ = 108469575961808. Its totient is φ = 54234787980900.

The previous prime is 81352181971343. The next prime is 81352181971367. The reversal of 81352181971353 is 35317918125318.

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 not a de Polignac number, because 81352181971353 - 2⁵ = 81352181971321 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 81352181971293 and 81352181971302.

It is not an unprimeable number, because it can be changed into a prime (81352181971303) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13558696995223 + ... + 13558696995228.

It is an arithmetic number, because the mean of its divisors is an integer number (27117393990452).

Almost surely, 2^{81352181971353} is an apocalyptic number.

It is an amenable number.

81352181971353 is a deficient number, since it is larger than the sum of its proper divisors (27117393990455).

81352181971353 is a wasteful number, since it uses less digits than its factorization.

81352181971353 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27117393990454.

The product of its digits is 5443200, while the sum is 57.

The spelling of 81352181971353 in words is "eighty-one trillion, three hundred fifty-two billion, one hundred eighty-one million, nine hundred seventy-one thousand, three hundred fifty-three".