1990403 has 4 divisors (see below), whose sum is σ = 2032800. Its totient is φ = 1948008.

The previous prime is 1990381. The next prime is 1990433. The reversal of 1990403 is 3040991.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1990403 - 2⁸ = 1990147 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1990433) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21128 + ... + 21221.

It is an arithmetic number, because the mean of its divisors is an integer number (508200).

2^1990403 is an apocalyptic number.

1990403 is a deficient number, since it is larger than the sum of its proper divisors (42397).

1990403 is an equidigital number, since it uses as much as digits as its factorization.

1990403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42396.

The product of its (nonzero) digits is 972, while the sum is 26.

The square root of 1990403 is about 1410.8164302984. The cubic root of 1990403 is about 125.7902574173.

The spelling of 1990403 in words is "one million, nine hundred ninety thousand, four hundred three".