55399121 has 2 divisors, whose sum is σ = 55399122. Its totient is φ = 55399120.

The previous prime is 55399103. The next prime is 55399129. The reversal of 55399121 is 12199355.

55399121 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., 49900096 + 5499025 = 7064^2 + 2345^2 .

It is a cyclic number.

It is not a de Polignac number, because 55399121 - 2¹⁰ = 55398097 is a prime.

It is not a weakly prime, because it can be changed into another prime (55399129) 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, 27699560 + 27699561.

It is an arithmetic number, because the mean of its divisors is an integer number (27699561).

Almost surely, 2^55399121 is an apocalyptic number.

It is an amenable number.

55399121 is a deficient number, since it is larger than the sum of its proper divisors (1).

55399121 is an equidigital number, since it uses as much as digits as its factorization.

55399121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12150, while the sum is 35.

The square root of 55399121 is about 7443.0585782996. The cubic root of 55399121 is about 381.2129317718.

The spelling of 55399121 in words is "fifty-five million, three hundred ninety-nine thousand, one hundred twenty-one".