12956557 has 4 divisors (see below), whose sum is σ = 13029120. Its totient is φ = 12883996.

The previous prime is 12956509. The next prime is 12956563. The reversal of 12956557 is 75565921.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 75565921 = 43 ⋅1757347.

It is a cyclic number.

It is not a de Polignac number, because 12956557 - 2¹⁵ = 12923789 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12956597) 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 3 ways as a sum of consecutive naturals, for example, 36013 + ... + 36370.

It is an arithmetic number, because the mean of its divisors is an integer number (3257280).

Almost surely, 2^12956557 is an apocalyptic number.

It is an amenable number.

12956557 is a deficient number, since it is larger than the sum of its proper divisors (72563).

12956557 is an equidigital number, since it uses as much as digits as its factorization.

12956557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72562.

The product of its digits is 94500, while the sum is 40.

The square root of 12956557 is about 3599.5217737916. The cubic root of 12956557 is about 234.8712558728.

The spelling of 12956557 in words is "twelve million, nine hundred fifty-six thousand, five hundred fifty-seven".