55000012121 has 2 divisors, whose sum is σ = 55000012122. Its totient is φ = 55000012120.

The previous prime is 55000012097. The next prime is 55000012153. The reversal of 55000012121 is 12121000055.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 53574194521 + 1425817600 = 231461^2 + 37760^2 .

It is a cyclic number.

It is not a de Polignac number, because 55000012121 - 2⁶ = 55000012057 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 55000012121.

It is not a weakly prime, because it can be changed into another prime (55000002121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27500006060 + 27500006061.

It is an arithmetic number, because the mean of its divisors is an integer number (27500006061).

Almost surely, 2^55000012121 is an apocalyptic number.

It is an amenable number.

55000012121 is a deficient number, since it is larger than the sum of its proper divisors (1).

55000012121 is an equidigital number, since it uses as much as digits as its factorization.

55000012121 is an odious number, because the sum of its binary digits is odd.

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

Adding to 55000012121 its reverse (12121000055), we get a palindrome (67121012176).

The spelling of 55000012121 in words is "fifty-five billion, twelve thousand, one hundred twenty-one".