617991197 has 2 divisors, whose sum is σ = 617991198. Its totient is φ = 617991196.

The previous prime is 617991181. The next prime is 617991263. The reversal of 617991197 is 791199716.

617991197 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 617969881 + 21316 = 24859^2 + 146^2 .

It is a cyclic number.

It is not a de Polignac number, because 617991197 - 2⁴ = 617991181 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (617991137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 308995598 + 308995599.

It is an arithmetic number, because the mean of its divisors is an integer number (308995599).

Almost surely, 2^617991197 is an apocalyptic number.

It is an amenable number.

617991197 is a deficient number, since it is larger than the sum of its proper divisors (1).

617991197 is an equidigital number, since it uses as much as digits as its factorization.

617991197 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 214326, while the sum is 50.

The square root of 617991197 is about 24859.4287343857. The cubic root of 617991197 is about 851.7799825140.

The spelling of 617991197 in words is "six hundred seventeen million, nine hundred ninety-one thousand, one hundred ninety-seven".