618598991 has 2 divisors, whose sum is σ = 618598992. Its totient is φ = 618598990.

The previous prime is 618598933. The next prime is 618598999. The reversal of 618598991 is 199895816.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 618598991 - 2⁶ = 618598927 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (618598999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 309299495 + 309299496.

It is an arithmetic number, because the mean of its divisors is an integer number (309299496).

Almost surely, 2^618598991 is an apocalyptic number.

618598991 is a deficient number, since it is larger than the sum of its proper divisors (1).

618598991 is an equidigital number, since it uses as much as digits as its factorization.

618598991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1399680, while the sum is 56.

The square root of 618598991 is about 24871.6503473332. The cubic root of 618598991 is about 852.0591327330.

The spelling of 618598991 in words is "six hundred eighteen million, five hundred ninety-eight thousand, nine hundred ninety-one".