1990903403 has 4 divisors (see below), whose sum is σ = 2018944368. Its totient is φ = 1962862440.

The previous prime is 1990903399. The next prime is 1990903417. The reversal of 1990903403 is 3043090991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3043090991 = 137 ⋅22212343.

It is a cyclic number.

It is not a de Polignac number, because 1990903403 - 2² = 1990903399 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1990903463) 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, 14020376 + ... + 14020517.

It is an arithmetic number, because the mean of its divisors is an integer number (504736092).

Almost surely, 2^1990903403 is an apocalyptic number.

1990903403 is a deficient number, since it is larger than the sum of its proper divisors (28040965).

1990903403 is an equidigital number, since it uses as much as digits as its factorization.

1990903403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28040964.

The product of its (nonzero) digits is 26244, while the sum is 38.

The square root of 1990903403 is about 44619.5405960214. The cubic root of 1990903403 is about 1258.0079808799.

The spelling of 1990903403 in words is "one billion, nine hundred ninety million, nine hundred three thousand, four hundred three".