198640549 has 2 divisors, whose sum is σ = 198640550. Its totient is φ = 198640548.

The previous prime is 198640543. The next prime is 198640567. The reversal of 198640549 is 945046891.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 144720900 + 53919649 = 12030^2 + 7343^2 .

It is an emirp because it is prime and its reverse (945046891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 198640549 - 2¹¹ = 198638501 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 198640499 and 198640508.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (198640543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99320274 + 99320275.

It is an arithmetic number, because the mean of its divisors is an integer number (99320275).

Almost surely, 2^198640549 is an apocalyptic number.

It is an amenable number.

198640549 is a deficient number, since it is larger than the sum of its proper divisors (1).

198640549 is an equidigital number, since it uses as much as digits as its factorization.

198640549 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 311040, while the sum is 46.

The square root of 198640549 is about 14093.9898183587. The cubic root of 198640549 is about 583.4755144759.

The spelling of 198640549 in words is "one hundred ninety-eight million, six hundred forty thousand, five hundred forty-nine".