1990671 has 4 divisors (see below), whose sum is σ = 2654232. Its totient is φ = 1327112.

The previous prime is 1990661. The next prime is 1990679. The reversal of 1990671 is 1760991.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1990671 - 2⁶ = 1990607 is a prime.

It is a D-number.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1990679) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 331776 + ... + 331781.

It is an arithmetic number, because the mean of its divisors is an integer number (663558).

2^1990671 is an apocalyptic number.

1990671 is a deficient number, since it is larger than the sum of its proper divisors (663561).

1990671 is an equidigital number, since it uses as much as digits as its factorization.

1990671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 663560.

The product of its (nonzero) digits is 3402, while the sum is 33.

The square root of 1990671 is about 1410.9114075660. The cubic root of 1990671 is about 125.7959028864.

The spelling of 1990671 in words is "one million, nine hundred ninety thousand, six hundred seventy-one".