12420557 has 8 divisors (see below), whose sum is σ = 13249656. Its totient is φ = 11602432.

The previous prime is 12420521. The next prime is 12420571. The reversal of 12420557 is 75502421.

12420557 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 8213956 + 4206601 = 2866^2 + 2051^2 .

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

It is a de Polignac number, because none of the positive numbers 2^k-12420557 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 (12420517) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 338 + ... + 4995.

It is an arithmetic number, because the mean of its divisors is an integer number (1656207).

Almost surely, 2^12420557 is an apocalyptic number.

12420557 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

12420557 is a deficient number, since it is larger than the sum of its proper divisors (829099).

12420557 is a wasteful number, since it uses less digits than its factorization.

12420557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5487.

The product of its (nonzero) digits is 2800, while the sum is 26.

The square root of 12420557 is about 3524.2810614365. The cubic root of 12420557 is about 231.5867407691.

Adding to 12420557 its reverse (75502421), we get a palindrome (87922978).

The spelling of 12420557 in words is "twelve million, four hundred twenty thousand, five hundred fifty-seven".