55507121 has 2 divisors, whose sum is σ = 55507122. Its totient is φ = 55507120.

The previous prime is 55507087. The next prime is 55507129. The reversal of 55507121 is 12170555.

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., 53290000 + 2217121 = 7300^2 + 1489^2 .

It is a cyclic number.

It is not a de Polignac number, because 55507121 - 2¹⁰ = 55506097 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (55507129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27753560 + 27753561.

It is an arithmetic number, because the mean of its divisors is an integer number (27753561).

Almost surely, 2^55507121 is an apocalyptic number.

It is an amenable number.

55507121 is a deficient number, since it is larger than the sum of its proper divisors (1).

55507121 is an equidigital number, since it uses as much as digits as its factorization.

55507121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1750, while the sum is 26.

The square root of 55507121 is about 7450.3101277732. The cubic root of 55507121 is about 381.4604944930.

Adding to 55507121 its reverse (12170555), we get a palindrome (67677676).

The spelling of 55507121 in words is "fifty-five million, five hundred seven thousand, one hundred twenty-one".