81144971 has 2 divisors, whose sum is σ = 81144972. Its totient is φ = 81144970.

The previous prime is 81144919. The next prime is 81144997. The reversal of 81144971 is 17944118.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81144971 - 2⁶ = 81144907 is a prime.

It is not a weakly prime, because it can be changed into another prime (81144901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40572485 + 40572486.

It is an arithmetic number, because the mean of its divisors is an integer number (40572486).

Almost surely, 2^81144971 is an apocalyptic number.

81144971 is a deficient number, since it is larger than the sum of its proper divisors (1).

81144971 is an equidigital number, since it uses as much as digits as its factorization.

81144971 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8064, while the sum is 35.

The square root of 81144971 is about 9008.0503439979. The cubic root of 81144971 is about 432.9328460910.

The spelling of 81144971 in words is "eighty-one million, one hundred forty-four thousand, nine hundred seventy-one".