1990243 has 2 divisors, whose sum is σ = 1990244. Its totient is φ = 1990242.

The previous prime is 1990237. The next prime is 1990249. The reversal of 1990243 is 3420991.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (1990237) and next prime (1990249).

It is a cyclic number.

It is not a de Polignac number, because 1990243 - 2⁵ = 1990211 is a prime.

It is a super-2 number, since 2×1990243² = 7922134398098, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1990249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 995121 + 995122.

It is an arithmetic number, because the mean of its divisors is an integer number (995122).

2^1990243 is an apocalyptic number.

1990243 is a deficient number, since it is larger than the sum of its proper divisors (1).

1990243 is an equidigital number, since it uses as much as digits as its factorization.

1990243 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 1990243 is about 1410.7597244038. The cubic root of 1990243 is about 125.7868867464.

The spelling of 1990243 in words is "one million, nine hundred ninety thousand, two hundred forty-three".