198611951 has 2 divisors, whose sum is σ = 198611952. Its totient is φ = 198611950.

The previous prime is 198611939. The next prime is 198611953. The reversal of 198611951 is 159116891.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (159116891) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-198611951 is a prime.

It is a Sophie Germain prime.

Together with 198611953, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 198611899 and 198611908.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (198611953) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99305975 + 99305976.

It is an arithmetic number, because the mean of its divisors is an integer number (99305976).

Almost surely, 2^198611951 is an apocalyptic number.

198611951 is a deficient number, since it is larger than the sum of its proper divisors (1).

198611951 is an equidigital number, since it uses as much as digits as its factorization.

198611951 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 19440, while the sum is 41.

The square root of 198611951 is about 14092.9752359110. The cubic root of 198611951 is about 583.4475124161.

It can be divided in two parts, 19861 and 1951, that added together give a palindrome (21812).

The spelling of 198611951 in words is "one hundred ninety-eight million, six hundred eleven thousand, nine hundred fifty-one".