12782557 has 4 divisors (see below), whose sum is σ = 12797856. Its totient is φ = 12767260.

The previous prime is 12782513. The next prime is 12782599. The reversal of 12782557 is 75528721.

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: 75528721 = 1993 ⋅37897.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12782557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12780557) 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, 6319 + ... + 8092.

It is an arithmetic number, because the mean of its divisors is an integer number (3199464).

Almost surely, 2^12782557 is an apocalyptic number.

It is an amenable number.

12782557 is a deficient number, since it is larger than the sum of its proper divisors (15299).

12782557 is an equidigital number, since it uses as much as digits as its factorization.

12782557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15298.

The product of its digits is 39200, while the sum is 37.

The square root of 12782557 is about 3575.2701995793. The cubic root of 12782557 is about 233.8151131672.

It can be divided in two parts, 1278 and 2557, that multiplied together give a triangular number (3267846 = T₂₅₅₆).

The spelling of 12782557 in words is "twelve million, seven hundred eighty-two thousand, five hundred fifty-seven".