12561663 has 8 divisors (see below), whose sum is σ = 16811776. Its totient is φ = 8343000.

The previous prime is 12561599. The next prime is 12561671. The reversal of 12561663 is 36616521.

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

It is not a de Polignac number, because 12561663 - 2⁶ = 12561599 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12561663.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12561163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6913 + ... + 8538.

It is an arithmetic number, because the mean of its divisors is an integer number (2101472).

Almost surely, 2^12561663 is an apocalyptic number.

12561663 is a deficient number, since it is larger than the sum of its proper divisors (4250113).

12561663 is a wasteful number, since it uses less digits than its factorization.

12561663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15725.

The product of its digits is 6480, while the sum is 30.

The square root of 12561663 is about 3544.2436428666. The cubic root of 12561663 is about 232.4604349371.

It can be divided in two parts, 12 and 561663, that multiplied together give a triangular number (6739956 = T₃₆₇₁).

The spelling of 12561663 in words is "twelve million, five hundred sixty-one thousand, six hundred sixty-three".