12405557 has 2 divisors, whose sum is σ = 12405558. Its totient is φ = 12405556.

The previous prime is 12405541. The next prime is 12405571. The reversal of 12405557 is 75550421.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11062276 + 1343281 = 3326^2 + 1159^2 .

It is a cyclic number.

It is not a de Polignac number, because 12405557 - 2⁴ = 12405541 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12405577) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6202778 + 6202779.

It is an arithmetic number, because the mean of its divisors is an integer number (6202779).

Almost surely, 2^12405557 is an apocalyptic number.

It is an amenable number.

12405557 is a deficient number, since it is larger than the sum of its proper divisors (1).

12405557 is an equidigital number, since it uses as much as digits as its factorization.

12405557 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7000, while the sum is 29.

The square root of 12405557 is about 3522.1523249286. The cubic root of 12405557 is about 231.4934760184.

Adding to 12405557 its reverse (75550421), we get a palindrome (87955978).

It can be divided in two parts, 12 and 405557, that multiplied together give a palindrome (4866684).

The spelling of 12405557 in words is "twelve million, four hundred five thousand, five hundred fifty-seven".