1990743 has 4 divisors (see below), whose sum is σ = 2654328. Its totient is φ = 1327160.

The previous prime is 1990693. The next prime is 1990753. The reversal of 1990743 is 3470991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3470991 = 3 ⋅1156997.

It is a cyclic number.

It is not a de Polignac number, because 1990743 - 2⁶ = 1990679 is a prime.

It is an Ulam number.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1990753) 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, 331788 + ... + 331793.

It is an arithmetic number, because the mean of its divisors is an integer number (663582).

2^1990743 is an apocalyptic number.

1990743 is a deficient number, since it is larger than the sum of its proper divisors (663585).

1990743 is an equidigital number, since it uses as much as digits as its factorization.

1990743 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 663584.

The product of its (nonzero) digits is 6804, while the sum is 33.

The square root of 1990743 is about 1410.9369227574. The cubic root of 1990743 is about 125.7974194932.

The spelling of 1990743 in words is "one million, nine hundred ninety thousand, seven hundred forty-three".