81521175343 has 2 divisors, whose sum is σ = 81521175344. Its totient is φ = 81521175342.

The previous prime is 81521175313. The next prime is 81521175353. The reversal of 81521175343 is 34357112518.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81521175343 - 2⁵ = 81521175311 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81521175296 and 81521175305.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81521175313) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40760587671 + 40760587672.

It is an arithmetic number, because the mean of its divisors is an integer number (40760587672).

Almost surely, 2^81521175343 is an apocalyptic number.

81521175343 is a deficient number, since it is larger than the sum of its proper divisors (1).

81521175343 is an equidigital number, since it uses as much as digits as its factorization.

81521175343 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 100800, while the sum is 40.

The spelling of 81521175343 in words is "eighty-one billion, five hundred twenty-one million, one hundred seventy-five thousand, three hundred forty-three".