12145581 has 18 divisors (see below), whose sum is σ = 20408622. Its totient is φ = 6940080.

The previous prime is 12145571. The next prime is 12145589. The reversal of 12145581 is 18554121.

It can be written as a sum of positive squares in only one way, i.e., 9922500 + 2223081 = 3150^2 + 1491^2 .

It is not a de Polignac number, because 12145581 - 2⁷ = 12145453 is a prime.

It is a super-2 number, since 2×12145581² = 295030275655122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12145589) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 13330 + ... + 14211.

Almost surely, 2^12145581 is an apocalyptic number.

It is an amenable number.

12145581 is a deficient number, since it is larger than the sum of its proper divisors (8263041).

12145581 is a wasteful number, since it uses less digits than its factorization.

12145581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27561 (or 27551 counting only the distinct ones).

The product of its digits is 1600, while the sum is 27.

The square root of 12145581 is about 3485.0510756659. The cubic root of 12145581 is about 229.8649553806.

The spelling of 12145581 in words is "twelve million, one hundred forty-five thousand, five hundred eighty-one".