55210121 has 4 divisors (see below), whose sum is σ = 55227600. Its totient is φ = 55192644.

The previous prime is 55210091. The next prime is 55210123. The reversal of 55210121 is 12101255.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12101255 = 5 ⋅2420251.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55210121 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 55210121.

It is not an unprimeable number, because it can be changed into a prime (55210123) 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 in 3 ways as a sum of consecutive naturals, for example, 2531 + ... + 10808.

It is an arithmetic number, because the mean of its divisors is an integer number (13806900).

Almost surely, 2^55210121 is an apocalyptic number.

It is an amenable number.

55210121 is a deficient number, since it is larger than the sum of its proper divisors (17479).

55210121 is a wasteful number, since it uses less digits than its factorization.

55210121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17478.

The product of its (nonzero) digits is 100, while the sum is 17.

The square root of 55210121 is about 7430.3513375883. The cubic root of 55210121 is about 380.7789216708.

Adding to 55210121 its reverse (12101255), we get a palindrome (67311376).

The spelling of 55210121 in words is "fifty-five million, two hundred ten thousand, one hundred twenty-one".