12821557 has 16 divisors (see below), whose sum is σ = 15466752. Its totient is φ = 10391040.

The previous prime is 12821551. The next prime is 12821579. The reversal of 12821557 is 75512821.

It is a cyclic number.

It is not a de Polignac number, because 12821557 - 2²³ = 4432949 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12821551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15207 + ... + 16027.

It is an arithmetic number, because the mean of its divisors is an integer number (966672).

Almost surely, 2^12821557 is an apocalyptic number.

It is an amenable number.

12821557 is a deficient number, since it is larger than the sum of its proper divisors (2645195).

12821557 is an equidigital number, since it uses as much as digits as its factorization.

12821557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 948.

The product of its digits is 5600, while the sum is 31.

The square root of 12821557 is about 3580.7201789584. The cubic root of 12821557 is about 234.0526642611.

The spelling of 12821557 in words is "twelve million, eight hundred twenty-one thousand, five hundred fifty-seven".