18001649 has 8 divisors (see below), whose sum is σ = 18724992. Its totient is φ = 17292240.

The previous prime is 18001639. The next prime is 18001673. The reversal of 18001649 is 94610081.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18001649 - 2⁸ = 18001393 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18001639) 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 7 ways as a sum of consecutive naturals, for example, 809 + ... + 6054.

It is an arithmetic number, because the mean of its divisors is an integer number (2340624).

Almost surely, 2^18001649 is an apocalyptic number.

It is an amenable number.

18001649 is a deficient number, since it is larger than the sum of its proper divisors (723343).

18001649 is an equidigital number, since it uses as much as digits as its factorization.

18001649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6967.

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 18001649 is about 4242.8350191823. The cubic root of 18001649 is about 262.0821421442.

The spelling of 18001649 in words is "eighteen million, one thousand, six hundred forty-nine".