12506421 has 16 divisors (see below), whose sum is σ = 17329664. Its totient is φ = 8016624.

The previous prime is 12506401. The next prime is 12506447. The reversal of 12506421 is 12460521.

It is a de Polignac number, because none of the positive numbers 2^k-12506421 is a prime.

It is a super-3 number, since 3×12506421³ (a number of 22 digits) contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12506401) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7920 + ... + 9366.

It is an arithmetic number, because the mean of its divisors is an integer number (1083104).

Almost surely, 2^12506421 is an apocalyptic number.

It is an amenable number.

12506421 is a deficient number, since it is larger than the sum of its proper divisors (4823243).

12506421 is a wasteful number, since it uses less digits than its factorization.

12506421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1560.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 12506421 is about 3536.4418558772. The cubic root of 12506421 is about 232.1191730675.

Adding to 12506421 its reverse (12460521), we get a palindrome (24966942).

The spelling of 12506421 in words is "twelve million, five hundred six thousand, four hundred twenty-one".