618188310781 has 2 divisors, whose sum is σ = 618188310782. Its totient is φ = 618188310780.

The previous prime is 618188310683. The next prime is 618188310791. The reversal of 618188310781 is 187013881816.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 461775970681 + 156412340100 = 679541^2 + 395490^2 .

It is a cyclic number.

It is not a de Polignac number, because 618188310781 - 2⁹ = 618188310269 is a prime.

It is a super-2 number, since 2×618188310781² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (618188310791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 309094155390 + 309094155391.

It is an arithmetic number, because the mean of its divisors is an integer number (309094155391).

Almost surely, 2^618188310781 is an apocalyptic number.

It is an amenable number.

618188310781 is a deficient number, since it is larger than the sum of its proper divisors (1).

618188310781 is an equidigital number, since it uses as much as digits as its factorization.

618188310781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 516096, while the sum is 52.

The spelling of 618188310781 in words is "six hundred eighteen billion, one hundred eighty-eight million, three hundred ten thousand, seven hundred eighty-one".