618989993 has 2 divisors, whose sum is σ = 618989994. Its totient is φ = 618989992.

The previous prime is 618989981. The next prime is 618990011. The reversal of 618989993 is 399989816.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 384042409 + 234947584 = 19597^2 + 15328^2 .

It is a cyclic number.

It is not a de Polignac number, because 618989993 - 2¹⁰ = 618988969 is a prime.

It is a super-2 number, since 2×618989993² = 766297222868280098, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (618989893) 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, 309494996 + 309494997.

It is an arithmetic number, because the mean of its divisors is an integer number (309494997).

Almost surely, 2^618989993 is an apocalyptic number.

It is an amenable number.

618989993 is a deficient number, since it is larger than the sum of its proper divisors (1).

618989993 is an equidigital number, since it uses as much as digits as its factorization.

618989993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7558272, while the sum is 62.

The square root of 618989993 is about 24879.5095007920. The cubic root of 618989993 is about 852.2386171599.

The spelling of 618989993 in words is "six hundred eighteen million, nine hundred eighty-nine thousand, nine hundred ninety-three".