81170143 has 2 divisors, whose sum is σ = 81170144. Its totient is φ = 81170142.

The previous prime is 81170129. The next prime is 81170153. The reversal of 81170143 is 34107118.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81170143 is a prime.

It is a super-2 number, since 2×81170143² = 13177184229280898, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81170153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40585071 + 40585072.

It is an arithmetic number, because the mean of its divisors is an integer number (40585072).

Almost surely, 2^81170143 is an apocalyptic number.

81170143 is a deficient number, since it is larger than the sum of its proper divisors (1).

81170143 is an equidigital number, since it uses as much as digits as its factorization.

81170143 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 672, while the sum is 25.

The square root of 81170143 is about 9009.4474303367. The cubic root of 81170143 is about 432.9776081952.

The spelling of 81170143 in words is "eighty-one million, one hundred seventy thousand, one hundred forty-three".