1998210397 has 2 divisors, whose sum is σ = 1998210398. Its totient is φ = 1998210396.

The previous prime is 1998210391. The next prime is 1998210421. The reversal of 1998210397 is 7930128991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1128019396 + 870191001 = 33586^2 + 29499^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1998210397 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1998210397.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1998210391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999105198 + 999105199.

It is an arithmetic number, because the mean of its divisors is an integer number (999105199).

Almost surely, 2^1998210397 is an apocalyptic number.

It is an amenable number.

1998210397 is a deficient number, since it is larger than the sum of its proper divisors (1).

1998210397 is an equidigital number, since it uses as much as digits as its factorization.

1998210397 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 244944, while the sum is 49.

The square root of 1998210397 is about 44701.3467023086. The cubic root of 1998210397 is about 1259.5451446706.

The spelling of 1998210397 in words is "one billion, nine hundred ninety-eight million, two hundred ten thousand, three hundred ninety-seven".