12643581 has 8 divisors (see below), whose sum is σ = 16904800. Its totient is φ = 8405712.

The previous prime is 12643573. The next prime is 12643613. The reversal of 12643581 is 18534621.

12643581 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 12643581 - 2³ = 12643573 is a prime.

It is a super-2 number, since 2×12643581² = 319720281007122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12643511) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4531 + ... + 6768.

It is an arithmetic number, because the mean of its divisors is an integer number (2113100).

Almost surely, 2^12643581 is an apocalyptic number.

It is an amenable number.

12643581 is a deficient number, since it is larger than the sum of its proper divisors (4261219).

12643581 is a wasteful number, since it uses less digits than its factorization.

12643581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11675.

The product of its digits is 5760, while the sum is 30.

The square root of 12643581 is about 3555.7813487334. The cubic root of 12643581 is about 232.9646529174.

The spelling of 12643581 in words is "twelve million, six hundred forty-three thousand, five hundred eighty-one".