55872121 has 2 divisors, whose sum is σ = 55872122. Its totient is φ = 55872120.

The previous prime is 55872079. The next prime is 55872127. The reversal of 55872121 is 12127855.

55872121 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., 44555625 + 11316496 = 6675^2 + 3364^2 .

It is a cyclic number.

It is not a de Polignac number, because 55872121 - 2¹⁵ = 55839353 is a prime.

It is not a weakly prime, because it can be changed into another prime (55872127) 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, 27936060 + 27936061.

It is an arithmetic number, because the mean of its divisors is an integer number (27936061).

Almost surely, 2^55872121 is an apocalyptic number.

It is an amenable number.

55872121 is a deficient number, since it is larger than the sum of its proper divisors (1).

55872121 is an equidigital number, since it uses as much as digits as its factorization.

55872121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5600, while the sum is 31.

The square root of 55872121 is about 7474.7656150544. The cubic root of 55872121 is about 382.2947958794.

Adding to 55872121 its reverse (12127855), we get a palindrome (67999976).

The spelling of 55872121 in words is "fifty-five million, eight hundred seventy-two thousand, one hundred twenty-one".