18912121201 has 2 divisors, whose sum is σ = 18912121202. Its totient is φ = 18912121200.

The previous prime is 18912121177. The next prime is 18912121271. The reversal of 18912121201 is 10212121981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11910448225 + 7001672976 = 109135^2 + 83676^2 .

It is an emirp because it is prime and its reverse (10212121981) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18912121201 - 2¹¹ = 18912119153 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18912121201.

It is not a weakly prime, because it can be changed into another prime (18912121271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9456060600 + 9456060601.

It is an arithmetic number, because the mean of its divisors is an integer number (9456060601).

Almost surely, 2^18912121201 is an apocalyptic number.

It is an amenable number.

18912121201 is a deficient number, since it is larger than the sum of its proper divisors (1).

18912121201 is an equidigital number, since it uses as much as digits as its factorization.

18912121201 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 28.

It can be divided in two parts, 18 and 912121201, that added together give a palindrome (912121219).

The spelling of 18912121201 in words is "eighteen billion, nine hundred twelve million, one hundred twenty-one thousand, two hundred one".