55121235504221 has 2 divisors, whose sum is σ = 55121235504222. Its totient is φ = 55121235504220.

The previous prime is 55121235504217. The next prime is 55121235504233. The reversal of 55121235504221 is 12240553212155.

55121235504221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 53407594802500 + 1713640701721 = 7308050^2 + 1309061^2 .

It is a cyclic number.

It is not a de Polignac number, because 55121235504221 - 2² = 55121235504217 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55121235504271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27560617752110 + 27560617752111.

It is an arithmetic number, because the mean of its divisors is an integer number (27560617752111).

Almost surely, 2^{55121235504221} is an apocalyptic number.

It is an amenable number.

55121235504221 is a deficient number, since it is larger than the sum of its proper divisors (1).

55121235504221 is an equidigital number, since it uses as much as digits as its factorization.

55121235504221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 120000, while the sum is 38.

Adding to 55121235504221 its reverse (12240553212155), we get a palindrome (67361788716376).

The spelling of 55121235504221 in words is "fifty-five trillion, one hundred twenty-one billion, two hundred thirty-five million, five hundred four thousand, two hundred twenty-one".