618313819661 has 2 divisors, whose sum is σ = 618313819662. Its totient is φ = 618313819660.

The previous prime is 618313819657. The next prime is 618313819681. The reversal of 618313819661 is 166918313816.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 610289064100 + 8024755561 = 781210^2 + 89581^2 .

It is a cyclic number.

It is not a de Polignac number, because 618313819661 - 2² = 618313819657 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (618313819681) 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, 309156909830 + 309156909831.

It is an arithmetic number, because the mean of its divisors is an integer number (309156909831).

Almost surely, 2^618313819661 is an apocalyptic number.

It is an amenable number.

618313819661 is a deficient number, since it is larger than the sum of its proper divisors (1).

618313819661 is an equidigital number, since it uses as much as digits as its factorization.

618313819661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1119744, while the sum is 53.

The spelling of 618313819661 in words is "six hundred eighteen billion, three hundred thirteen million, eight hundred nineteen thousand, six hundred sixty-one".