1990171 has 2 divisors, whose sum is σ = 1990172. Its totient is φ = 1990170.

The previous prime is 1990159. The next prime is 1990187. The reversal of 1990171 is 1710991.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1990171 is a prime.

It is not a weakly prime, because it can be changed into another prime (1990111) 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, 995085 + 995086.

It is an arithmetic number, because the mean of its divisors is an integer number (995086).

2^1990171 is an apocalyptic number.

1990171 is a deficient number, since it is larger than the sum of its proper divisors (1).

1990171 is an equidigital number, since it uses as much as digits as its factorization.

1990171 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 567, while the sum is 28.

The square root of 1990171 is about 1410.7342060076. The cubic root of 1990171 is about 125.7853698855.

The spelling of 1990171 in words is "one million, nine hundred ninety thousand, one hundred seventy-one".