1990897 has 4 divisors (see below), whose sum is σ = 2005360. Its totient is φ = 1976436.

The previous prime is 1990889. The next prime is 1990907. The reversal of 1990897 is 7980991.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 7980991 = 1697 ⋅4703.

It is a cyclic number.

It is not a de Polignac number, because 1990897 - 2³ = 1990889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1990867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7023 + ... + 7300.

It is an arithmetic number, because the mean of its divisors is an integer number (501340).

2^1990897 is an apocalyptic number.

It is an amenable number.

1990897 is a deficient number, since it is larger than the sum of its proper divisors (14463).

1990897 is a wasteful number, since it uses less digits than its factorization.

1990897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14462.

The product of its (nonzero) digits is 40824, while the sum is 43.

The square root of 1990897 is about 1410.9914953677. The cubic root of 1990897 is about 125.8006632240.

The spelling of 1990897 in words is "one million, nine hundred ninety thousand, eight hundred ninety-seven".