3603991 has 2 divisors, whose sum is σ = 3603992. Its totient is φ = 3603990.

The previous prime is 3603989. The next prime is 3604019. The reversal of 3603991 is 1993063.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 3603991 - 2¹ = 3603989 is a prime.

It is a super-2 number, since 2×3603991² = 25977502256162, which contains 22 as substring.

Together with 3603989, it forms a pair of twin primes.

It is equal to p₂₅₆₉₉₀ and since 3603991 and 256990 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3603931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1801995 + 1801996.

It is an arithmetic number, because the mean of its divisors is an integer number (1801996).

Almost surely, 2^3603991 is an apocalyptic number.

3603991 is a deficient number, since it is larger than the sum of its proper divisors (1).

3603991 is an equidigital number, since it uses as much as digits as its factorization.

3603991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4374, while the sum is 31.

The square root of 3603991 is about 1898.4180256203. The cubic root of 3603991 is about 153.3185015059.

The spelling of 3603991 in words is "three million, six hundred three thousand, nine hundred ninety-one".