81343187 has 2 divisors, whose sum is σ = 81343188. Its totient is φ = 81343186.

The previous prime is 81343177. The next prime is 81343189. The reversal of 81343187 is 78134318.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81343187 - 2⁸ = 81342931 is a prime.

Together with 81343189, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81343189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40671593 + 40671594.

It is an arithmetic number, because the mean of its divisors is an integer number (40671594).

Almost surely, 2^81343187 is an apocalyptic number.

81343187 is a deficient number, since it is larger than the sum of its proper divisors (1).

81343187 is an equidigital number, since it uses as much as digits as its factorization.

81343187 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16128, while the sum is 35.

The square root of 81343187 is about 9019.0457921002. The cubic root of 81343187 is about 433.2850734553.

The spelling of 81343187 in words is "eighty-one million, three hundred forty-three thousand, one hundred eighty-seven".