199784479 has 2 divisors, whose sum is σ = 199784480. Its totient is φ = 199784478.

The previous prime is 199784477. The next prime is 199784483. The reversal of 199784479 is 974487991.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 199784479 - 2¹ = 199784477 is a prime.

Together with 199784477, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199784477) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99892239 + 99892240.

It is an arithmetic number, because the mean of its divisors is an integer number (99892240).

Almost surely, 2^199784479 is an apocalyptic number.

199784479 is a deficient number, since it is larger than the sum of its proper divisors (1).

199784479 is an equidigital number, since it uses as much as digits as its factorization.

199784479 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4572288, while the sum is 58.

The square root of 199784479 is about 14134.5137518063. The cubic root of 199784479 is about 584.5934097336.

The spelling of 199784479 in words is "one hundred ninety-nine million, seven hundred eighty-four thousand, four hundred seventy-nine".