3646991 has 4 divisors (see below), whose sum is σ = 3735984. Its totient is φ = 3558000.

The previous prime is 3646963. The next prime is 3646997. The reversal of 3646991 is 1996463.

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 3646991 - 2⁶ = 3646927 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3646997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44435 + ... + 44516.

It is an arithmetic number, because the mean of its divisors is an integer number (933996).

Almost surely, 2^3646991 is an apocalyptic number.

3646991 is a deficient number, since it is larger than the sum of its proper divisors (88993).

3646991 is an equidigital number, since it uses as much as digits as its factorization.

3646991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88992.

The product of its digits is 34992, while the sum is 38.

The square root of 3646991 is about 1909.7096637971. The cubic root of 3646991 is about 153.9258511878.

The spelling of 3646991 in words is "three million, six hundred forty-six thousand, nine hundred ninety-one".