618820557444121 has 2 divisors, whose sum is σ = 618820557444122. Its totient is φ = 618820557444120.

The previous prime is 618820557444113. The next prime is 618820557444203. The reversal of 618820557444121 is 121444755028816.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 477643647603600 + 141176909840521 = 21855060^2 + 11881789^2 .

It is a cyclic number.

It is not a de Polignac number, because 618820557444121 - 2³ = 618820557444113 is a prime.

It is not a weakly prime, because it can be changed into another prime (618820537444121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 309410278722060 + 309410278722061.

It is an arithmetic number, because the mean of its divisors is an integer number (309410278722061).

Almost surely, 2^{618820557444121} is an apocalyptic number.

It is an amenable number.

618820557444121 is a deficient number, since it is larger than the sum of its proper divisors (1).

618820557444121 is an equidigital number, since it uses as much as digits as its factorization.

618820557444121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17203200, while the sum is 58.

The spelling of 618820557444121 in words is "six hundred eighteen trillion, eight hundred twenty billion, five hundred fifty-seven million, four hundred forty-four thousand, one hundred twenty-one".