55028381 has 2 divisors, whose sum is σ = 55028382. Its totient is φ = 55028380.

The previous prime is 55028377. The next prime is 55028383. The reversal of 55028381 is 18382055.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 36409156 + 18619225 = 6034^2 + 4315^2 .

It is a cyclic number.

It is not a de Polignac number, because 55028381 - 2² = 55028377 is a prime.

It is a super-2 number, since 2×55028381² = 6056245430962322, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 55028383, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55028383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27514190 + 27514191.

It is an arithmetic number, because the mean of its divisors is an integer number (27514191).

Almost surely, 2^55028381 is an apocalyptic number.

It is an amenable number.

55028381 is a deficient number, since it is larger than the sum of its proper divisors (1).

55028381 is an equidigital number, since it uses as much as digits as its factorization.

55028381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9600, while the sum is 32.

The square root of 55028381 is about 7418.1116869457. Note that the first 3 decimals coincide. The cubic root of 55028381 is about 380.3606479151.

The spelling of 55028381 in words is "fifty-five million, twenty-eight thousand, three hundred eighty-one".