81985103 has 2 divisors, whose sum is σ = 81985104. Its totient is φ = 81985102.

The previous prime is 81985097. The next prime is 81985121. The reversal of 81985103 is 30158918.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81985103 - 2⁶ = 81985039 is a prime.

It is a super-2 number, since 2×81985103² = 13443114227841218, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81981103) 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, 40992551 + 40992552.

It is an arithmetic number, because the mean of its divisors is an integer number (40992552).

Almost surely, 2^81985103 is an apocalyptic number.

81985103 is a deficient number, since it is larger than the sum of its proper divisors (1).

81985103 is an equidigital number, since it uses as much as digits as its factorization.

81985103 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 35.

The square root of 81985103 is about 9054.5625515538. The cubic root of 81985103 is about 434.4218381458.

The spelling of 81985103 in words is "eighty-one million, nine hundred eighty-five thousand, one hundred three".