1990945 has 16 divisors (see below), whose sum is σ = 2659392. Its totient is φ = 1418560.

The previous prime is 1990939. The next prime is 1990951. The reversal of 1990945 is 5490991.

It is an interprime number because it is at equal distance from previous prime (1990939) and next prime (1990951).

It is not a de Polignac number, because 1990945 - 2⁹ = 1990433 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2574 + ... + 3256.

It is an arithmetic number, because the mean of its divisors is an integer number (166212).

2^1990945 is an apocalyptic number.

It is an amenable number.

1990945 is a deficient number, since it is larger than the sum of its proper divisors (668447).

1990945 is a wasteful number, since it uses less digits than its factorization.

1990945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 752.

The product of its (nonzero) digits is 14580, while the sum is 37.

The square root of 1990945 is about 1411.0085045810. The cubic root of 1990945 is about 125.8016742228.

The spelling of 1990945 in words is "one million, nine hundred ninety thousand, nine hundred forty-five".