3556991 has 2 divisors, whose sum is σ = 3556992. Its totient is φ = 3556990.

The previous prime is 3556981. The next prime is 3556999. The reversal of 3556991 is 1996553.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 3556991 - 2¹⁰ = 3555967 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3556999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1778495 + 1778496.

It is an arithmetic number, because the mean of its divisors is an integer number (1778496).

Almost surely, 2^3556991 is an apocalyptic number.

3556991 is a deficient number, since it is larger than the sum of its proper divisors (1).

3556991 is an equidigital number, since it uses as much as digits as its factorization.

3556991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36450, while the sum is 38.

The square root of 3556991 is about 1885.9986744428. The cubic root of 3556991 is about 152.6491025816.

The spelling of 3556991 in words is "three million, five hundred fifty-six thousand, nine hundred ninety-one".