55110721 has 2 divisors, whose sum is σ = 55110722. Its totient is φ = 55110720.

The previous prime is 55110689. The next prime is 55110733. The reversal of 55110721 is 12701155.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 34680321 + 20430400 = 5889^2 + 4520^2 .

It is a cyclic number.

It is not a de Polignac number, because 55110721 - 2⁵ = 55110689 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 55110692 and 55110701.

It is not a weakly prime, because it can be changed into another prime (55110221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27555360 + 27555361.

It is an arithmetic number, because the mean of its divisors is an integer number (27555361).

Almost surely, 2^55110721 is an apocalyptic number.

It is an amenable number.

55110721 is a deficient number, since it is larger than the sum of its proper divisors (1).

55110721 is an equidigital number, since it uses as much as digits as its factorization.

55110721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 350, while the sum is 22.

The square root of 55110721 is about 7423.6595423012. The cubic root of 55110721 is about 380.5502669634.

Adding to 55110721 its reverse (12701155), we get a palindrome (67811876).

The spelling of 55110721 in words is "fifty-five million, one hundred ten thousand, seven hundred twenty-one".