12557661 has 8 divisors (see below), whose sum is σ = 17059680. Its totient is φ = 8213712.

The previous prime is 12557659. The next prime is 12557693. The reversal of 12557661 is 16675521.

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

It is not a de Polignac number, because 12557661 - 2¹ = 12557659 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12557641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39331 + ... + 39648.

It is an arithmetic number, because the mean of its divisors is an integer number (2132460).

Almost surely, 2^12557661 is an apocalyptic number.

It is an amenable number.

12557661 is a deficient number, since it is larger than the sum of its proper divisors (4502019).

12557661 is an equidigital number, since it uses as much as digits as its factorization.

12557661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79035.

The product of its digits is 12600, while the sum is 33.

The square root of 12557661 is about 3543.6790204532. The cubic root of 12557661 is about 232.4357459164.

The spelling of 12557661 in words is "twelve million, five hundred fifty-seven thousand, six hundred sixty-one".