198777967 has 4 divisors (see below), whose sum is σ = 198842256. Its totient is φ = 198713680.

The previous prime is 198777947. The next prime is 198777989. The reversal of 198777967 is 769777891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 769777891 = 47 ⋅16378253.

It is a cyclic number.

It is not a de Polignac number, because 198777967 - 2¹¹ = 198775919 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198777947) 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 in 3 ways as a sum of consecutive naturals, for example, 27259 + ... + 33772.

It is an arithmetic number, because the mean of its divisors is an integer number (49710564).

Almost surely, 2^198777967 is an apocalyptic number.

198777967 is a deficient number, since it is larger than the sum of its proper divisors (64289).

198777967 is an equidigital number, since it uses as much as digits as its factorization.

198777967 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64288.

The product of its digits is 9335088, while the sum is 61.

The square root of 198777967 is about 14098.8640322545. The cubic root of 198777967 is about 583.6100314152.

The spelling of 198777967 in words is "one hundred ninety-eight million, seven hundred seventy-seven thousand, nine hundred sixty-seven".