1998372617 has 2 divisors, whose sum is σ = 1998372618. Its totient is φ = 1998372616.

The previous prime is 1998372587. The next prime is 1998372631. The reversal of 1998372617 is 7162738991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1862440336 + 135932281 = 43156^2 + 11659^2 .

It is a cyclic number.

It is not a de Polignac number, because 1998372617 - 2⁸ = 1998372361 is a prime.

It is not a weakly prime, because it can be changed into another prime (1998372637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999186308 + 999186309.

It is an arithmetic number, because the mean of its divisors is an integer number (999186309).

Almost surely, 2^1998372617 is an apocalyptic number.

It is an amenable number.

1998372617 is a deficient number, since it is larger than the sum of its proper divisors (1).

1998372617 is an equidigital number, since it uses as much as digits as its factorization.

1998372617 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1143072, while the sum is 53.

The square root of 1998372617 is about 44703.1611522049. The cubic root of 1998372617 is about 1259.5792281493.

The spelling of 1998372617 in words is "one billion, nine hundred ninety-eight million, three hundred seventy-two thousand, six hundred seventeen".