12628381 has 2 divisors, whose sum is σ = 12628382. Its totient is φ = 12628380.

The previous prime is 12628379. The next prime is 12628391. The reversal of 12628381 is 18382621.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8608356 + 4020025 = 2934^2 + 2005^2 .

It is a cyclic number.

It is not a de Polignac number, because 12628381 - 2¹ = 12628379 is a prime.

It is a super-2 number, since 2×12628381² = 318952013362322, which contains 22 as substring.

Together with 12628379, it forms a pair of twin primes.

It is equal to p₈₂₆₅₅₅ and since 12628381 and 826555 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12628321) 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 as a sum of consecutive naturals, namely, 6314190 + 6314191.

It is an arithmetic number, because the mean of its divisors is an integer number (6314191).

Almost surely, 2^12628381 is an apocalyptic number.

It is an amenable number.

12628381 is a deficient number, since it is larger than the sum of its proper divisors (1).

12628381 is an equidigital number, since it uses as much as digits as its factorization.

12628381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4608, while the sum is 31.

The square root of 12628381 is about 3553.6433416988. The cubic root of 12628381 is about 232.8712594744.

The spelling of 12628381 in words is "twelve million, six hundred twenty-eight thousand, three hundred eighty-one".