900003991 has 2 divisors, whose sum is σ = 900003992. Its totient is φ = 900003990.

The previous prime is 900003983. The next prime is 900004019. The reversal of 900003991 is 199300009.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 900003991 - 2³ = 900003983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (900003901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 450001995 + 450001996.

It is an arithmetic number, because the mean of its divisors is an integer number (450001996).

Almost surely, 2^900003991 is an apocalyptic number.

900003991 is a deficient number, since it is larger than the sum of its proper divisors (1).

900003991 is an equidigital number, since it uses as much as digits as its factorization.

900003991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2187, while the sum is 31.

The square root of 900003991 is about 30000.0665165929. The cubic root of 900003991 is about 965.4908117399.

The spelling of 900003991 in words is "nine hundred million, three thousand, nine hundred ninety-one".