12561407 has 4 divisors (see below), whose sum is σ = 12571536. Its totient is φ = 12551280.

The previous prime is 12561401. The next prime is 12561431. The reversal of 12561407 is 70416521.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 12561407 - 2¹⁸ = 12299263 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12561401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2894 + ... + 5787.

It is an arithmetic number, because the mean of its divisors is an integer number (3142884).

Almost surely, 2^12561407 is an apocalyptic number.

12561407 is the 2894-th pentagonal number.

12561407 is a deficient number, since it is larger than the sum of its proper divisors (10129).

12561407 is an equidigital number, since it uses as much as digits as its factorization.

12561407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10128.

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 12561407 is about 3544.2075277839. The cubic root of 12561407 is about 232.4588557864.

Adding to 12561407 its reverse (70416521), we get a palindrome (82977928).

The spelling of 12561407 in words is "twelve million, five hundred sixty-one thousand, four hundred seven".