18198779 has 2 divisors, whose sum is σ = 18198780. Its totient is φ = 18198778.

The previous prime is 18198757. The next prime is 18198781. The reversal of 18198779 is 97789181.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18198779 is a prime.

Together with 18198781, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18198799) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9099389 + 9099390.

It is an arithmetic number, because the mean of its divisors is an integer number (9099390).

Almost surely, 2^18198779 is an apocalyptic number.

18198779 is a deficient number, since it is larger than the sum of its proper divisors (1).

18198779 is an equidigital number, since it uses as much as digits as its factorization.

18198779 is an evil number, because the sum of its binary digits is even.

The product of its digits is 254016, while the sum is 50.

The square root of 18198779 is about 4266.0026957329. The cubic root of 18198779 is about 263.0353290018.

The spelling of 18198779 in words is "eighteen million, one hundred ninety-eight thousand, seven hundred seventy-nine".