198778553 has 2 divisors, whose sum is σ = 198778554. Its totient is φ = 198778552.

The previous prime is 198778549. The next prime is 198778571. The reversal of 198778553 is 355877891.

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., 103286569 + 95491984 = 10163^2 + 9772^2 .

It is an emirp because it is prime and its reverse (355877891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 198778553 - 2² = 198778549 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 198778495 and 198778504.

It is not a weakly prime, because it can be changed into another prime (198778583) 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, 99389276 + 99389277.

It is an arithmetic number, because the mean of its divisors is an integer number (99389277).

Almost surely, 2^198778553 is an apocalyptic number.

It is an amenable number.

198778553 is a deficient number, since it is larger than the sum of its proper divisors (1).

198778553 is an equidigital number, since it uses as much as digits as its factorization.

198778553 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2116800, while the sum is 53.

The square root of 198778553 is about 14098.8848140553. The cubic root of 198778553 is about 583.6106049113.

The spelling of 198778553 in words is "one hundred ninety-eight million, seven hundred seventy-eight thousand, five hundred fifty-three".