55628381 has 2 divisors, whose sum is σ = 55628382. Its totient is φ = 55628380.

The previous prime is 55628347. The next prime is 55628407. The reversal of 55628381 is 18382655.

55628381 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51984100 + 3644281 = 7210^2 + 1909^2 .

It is a cyclic number.

It is not a de Polignac number, because 55628381 - 2⁶ = 55628317 is a prime.

It is a super-2 number, since 2×55628381² = 6189033545362322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55628281) by changing a digit.

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 as a sum of consecutive naturals, namely, 27814190 + 27814191.

It is an arithmetic number, because the mean of its divisors is an integer number (27814191).

Almost surely, 2^55628381 is an apocalyptic number.

It is an amenable number.

55628381 is a deficient number, since it is larger than the sum of its proper divisors (1).

55628381 is an equidigital number, since it uses as much as digits as its factorization.

55628381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 57600, while the sum is 38.

The square root of 55628381 is about 7458.4436043990. The cubic root of 55628381 is about 381.7380700319.

The spelling of 55628381 in words is "fifty-five million, six hundred twenty-eight thousand, three hundred eighty-one".