198777947 has 2 divisors, whose sum is σ = 198777948. Its totient is φ = 198777946.

The previous prime is 198777911. The next prime is 198777989. The reversal of 198777947 is 749777891.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 198777947 - 2¹² = 198773851 is a prime.

It is not a weakly prime, because it can be changed into another prime (191777947) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99388973 + 99388974.

It is an arithmetic number, because the mean of its divisors is an integer number (99388974).

Almost surely, 2^198777947 is an apocalyptic number.

198777947 is a deficient number, since it is larger than the sum of its proper divisors (1).

198777947 is an equidigital number, since it uses as much as digits as its factorization.

198777947 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6223392, while the sum is 59.

The square root of 198777947 is about 14098.8633229775. The cubic root of 198777947 is about 583.6100118419.

The spelling of 198777947 in words is "one hundred ninety-eight million, seven hundred seventy-seven thousand, nine hundred forty-seven".