12001581 has 16 divisors (see below), whose sum is σ = 17846400. Its totient is φ = 7971264.

The previous prime is 12001571. The next prime is 12001667. The reversal of 12001581 is 18510021.

12001581 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 not a de Polignac number, because 12001581 - 2⁷ = 12001453 is a prime.

It is a super-2 number, since 2×12001581² = 288075892999122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12001511) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8440 + ... + 9758.

It is an arithmetic number, because the mean of its divisors is an integer number (1115400).

Almost surely, 2^12001581 is an apocalyptic number.

It is an amenable number.

12001581 is a deficient number, since it is larger than the sum of its proper divisors (5844819).

12001581 is a wasteful number, since it uses less digits than its factorization.

12001581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1665 (or 1659 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 18.

The square root of 12001581 is about 3464.3298053159. The cubic root of 12001581 is about 228.9529024759.

The spelling of 12001581 in words is "twelve million, one thousand, five hundred eighty-one".