198786145 has 4 divisors (see below), whose sum is σ = 238543380. Its totient is φ = 159028912.

The previous prime is 198786121. The next prime is 198786149. The reversal of 198786145 is 541687891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 541687891 = 19 ⋅28509889.

It can be written as a sum of positive squares in 2 ways, for example, as 153735201 + 45050944 = 12399^2 + 6712^2 .

It is a cyclic number.

It is not a de Polignac number, because 198786145 - 2¹¹ = 198784097 is a prime.

It is a super-2 number, since 2×198786145² = 79031862887922050, which contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (198786149) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19878610 + ... + 19878619.

It is an arithmetic number, because the mean of its divisors is an integer number (59635845).

Almost surely, 2^198786145 is an apocalyptic number.

It is an amenable number.

198786145 is a deficient number, since it is larger than the sum of its proper divisors (39757235).

198786145 is an equidigital number, since it uses as much as digits as its factorization.

198786145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39757234.

The product of its digits is 483840, while the sum is 49.

The square root of 198786145 is about 14099.1540526373. The cubic root of 198786145 is about 583.6180348129.

The spelling of 198786145 in words is "one hundred ninety-eight million, seven hundred eighty-six thousand, one hundred forty-five".