12001644 has 36 divisors (see below), whose sum is σ = 31047016. Its totient is φ = 3907008.

The previous prime is 12001571. The next prime is 12001667. The reversal of 12001644 is 44610021.

12001644 is a `hidden beast` number, since 1 + 20 + 0 + 1 + 644 = 666.

12001644 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2329 + ... + 5424.

Almost surely, 2^12001644 is an apocalyptic number.

It is an amenable number.

12001644 is an abundant number, since it is smaller than the sum of its proper divisors (19045372).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12001644 is a wasteful number, since it uses less digits than its factorization.

12001644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7806 (or 7801 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 12001644 is about 3464.3388979717. The cubic root of 12001644 is about 228.9533030900.

Adding to 12001644 its reverse (44610021), we get a palindrome (56611665).

The spelling of 12001644 in words is "twelve million, one thousand, six hundred forty-four".