198637961 has 2 divisors, whose sum is σ = 198637962. Its totient is φ = 198637960.

The previous prime is 198637927. The next prime is 198637973. The reversal of 198637961 is 169736891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 168870025 + 29767936 = 12995^2 + 5456^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-198637961 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (198637991) 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, 99318980 + 99318981.

It is an arithmetic number, because the mean of its divisors is an integer number (99318981).

Almost surely, 2^198637961 is an apocalyptic number.

It is an amenable number.

198637961 is a deficient number, since it is larger than the sum of its proper divisors (1).

198637961 is an equidigital number, since it uses as much as digits as its factorization.

198637961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 489888, while the sum is 50.

The square root of 198637961 is about 14093.8980058747. The cubic root of 198637961 is about 583.4729805166.

The spelling of 198637961 in words is "one hundred ninety-eight million, six hundred thirty-seven thousand, nine hundred sixty-one".