1191218423 has 2 divisors, whose sum is σ = 1191218424. Its totient is φ = 1191218422.

The previous prime is 1191218389. The next prime is 1191218429. The reversal of 1191218423 is 3248121911.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1191218423 - 2⁶ = 1191218359 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1191218423.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1191218429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 595609211 + 595609212.

It is an arithmetic number, because the mean of its divisors is an integer number (595609212).

Almost surely, 2^1191218423 is an apocalyptic number.

1191218423 is a deficient number, since it is larger than the sum of its proper divisors (1).

1191218423 is an equidigital number, since it uses as much as digits as its factorization.

1191218423 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3456, while the sum is 32.

The square root of 1191218423 is about 34514.0322622553. The cubic root of 1191218423 is about 1060.0600485147.

The spelling of 1191218423 in words is "one billion, one hundred ninety-one million, two hundred eighteen thousand, four hundred twenty-three".