1990823 has 2 divisors, whose sum is σ = 1990824. Its totient is φ = 1990822.

The previous prime is 1990787. The next prime is 1990829. The reversal of 1990823 is 3280991.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1990823 - 2⁶ = 1990759 is a prime.

It is a super-3 number, since 3×1990823³ = 23671141593334715301, which contains 333 as substring.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1990823.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1990829) 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 as a sum of consecutive naturals, namely, 995411 + 995412.

It is an arithmetic number, because the mean of its divisors is an integer number (995412).

2^1990823 is an apocalyptic number.

1990823 is a deficient number, since it is larger than the sum of its proper divisors (1).

1990823 is an equidigital number, since it uses as much as digits as its factorization.

1990823 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 1990823 is about 1410.9652724288. The cubic root of 1990823 is about 125.7991045691.

The spelling of 1990823 in words is "one million, nine hundred ninety thousand, eight hundred twenty-three".