12420556 has 12 divisors (see below), whose sum is σ = 21767760. Its totient is φ = 6201200.

The previous prime is 12420521. The next prime is 12420571. The reversal of 12420556 is 65502421.

It is a super-2 number, since 2×12420556² = 308540422698272, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 12420556.

It is a congruent number.

It is an unprimeable number.

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, 1506 + ... + 5206.

It is an arithmetic number, because the mean of its divisors is an integer number (1813980).

Almost surely, 2^12420556 is an apocalyptic number.

It is an amenable number.

12420556 is a deficient number, since it is larger than the sum of its proper divisors (9347204).

12420556 is a wasteful number, since it uses less digits than its factorization.

12420556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4544 (or 4542 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 12420556 is about 3524.2809195636. The cubic root of 12420556 is about 231.5867345540.

Adding to 12420556 its reverse (65502421), we get a palindrome (77922977).

The spelling of 12420556 in words is "twelve million, four hundred twenty thousand, five hundred fifty-six".