18001645 has 8 divisors (see below), whose sum is σ = 22739040. Its totient is φ = 13643280.

The previous prime is 18001639. The next prime is 18001673. The reversal of 18001645 is 54610081.

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

It is a de Polignac number, because none of the positive numbers 2^k-18001645 is a prime.

It is a super-3 number, since 3×18001645³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 94651 + ... + 94840.

It is an arithmetic number, because the mean of its divisors is an integer number (2842380).

Almost surely, 2^18001645 is an apocalyptic number.

It is an amenable number.

18001645 is a deficient number, since it is larger than the sum of its proper divisors (4737395).

18001645 is a wasteful number, since it uses less digits than its factorization.

18001645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189515.

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 18001645 is about 4242.8345477994. The cubic root of 18001645 is about 262.0821227325.

The spelling of 18001645 in words is "eighteen million, one thousand, six hundred forty-five".