12131561 has 8 divisors (see below), whose sum is σ = 13125504. Its totient is φ = 11146320.

The previous prime is 12131549. The next prime is 12131563. The reversal of 12131561 is 16513121.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12131561 is a prime.

It is a super-3 number, since 3×12131561³ (a number of 22 digits) contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (12131563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 896 + ... + 5006.

It is an arithmetic number, because the mean of its divisors is an integer number (1640688).

Almost surely, 2^12131561 is an apocalyptic number.

It is an amenable number.

12131561 is a deficient number, since it is larger than the sum of its proper divisors (993943).

12131561 is a wasteful number, since it uses less digits than its factorization.

12131561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4351.

The product of its digits is 180, while the sum is 20.

The square root of 12131561 is about 3483.0390465799. The cubic root of 12131561 is about 229.7764747090.

Adding to 12131561 its reverse (16513121), we get a palindrome (28644682).

The spelling of 12131561 in words is "twelve million, one hundred thirty-one thousand, five hundred sixty-one".