81211003 has 2 divisors, whose sum is σ = 81211004. Its totient is φ = 81211002.

The previous prime is 81210977. The next prime is 81211027. The reversal of 81211003 is 30011218.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81211003 - 2¹⁷ = 81079931 is a prime.

It is not a weakly prime, because it can be changed into another prime (81211033) 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, 40605501 + 40605502.

It is an arithmetic number, because the mean of its divisors is an integer number (40605502).

Almost surely, 2^81211003 is an apocalyptic number.

81211003 is a deficient number, since it is larger than the sum of its proper divisors (1).

81211003 is an equidigital number, since it uses as much as digits as its factorization.

81211003 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48, while the sum is 16.

The square root of 81211003 is about 9011.7147646827. The cubic root of 81211003 is about 433.0502477836.

The spelling of 81211003 in words is "eighty-one million, two hundred eleven thousand, three".