1990871 has 2 divisors, whose sum is σ = 1990872. Its totient is φ = 1990870.

The previous prime is 1990867. The next prime is 1990883. The reversal of 1990871 is 1780991.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1990871 - 2² = 1990867 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1990831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 995435 + 995436.

It is an arithmetic number, because the mean of its divisors is an integer number (995436).

2^1990871 is an apocalyptic number.

1990871 is a deficient number, since it is larger than the sum of its proper divisors (1).

1990871 is an equidigital number, since it uses as much as digits as its factorization.

1990871 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4536, while the sum is 35.

The square root of 1990871 is about 1410.9822819582. The cubic root of 1990871 is about 125.8001155929.

The spelling of 1990871 in words is "one million, nine hundred ninety thousand, eight hundred seventy-one".