123991379 has 2 divisors, whose sum is σ = 123991380. Its totient is φ = 123991378.

The previous prime is 123991313. The next prime is 123991381. The reversal of 123991379 is 973199321.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123991379 is a prime.

Together with 123991381, 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 (123991079) 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 as a sum of consecutive naturals, namely, 61995689 + 61995690.

It is an arithmetic number, because the mean of its divisors is an integer number (61995690).

Almost surely, 2^123991379 is an apocalyptic number.

123991379 is a deficient number, since it is larger than the sum of its proper divisors (1).

123991379 is an equidigital number, since it uses as much as digits as its factorization.

123991379 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 91854, while the sum is 44.

The square root of 123991379 is about 11135.1416246045. The cubic root of 123991379 is about 498.6515385729.

The spelling of 123991379 in words is "one hundred twenty-three million, nine hundred ninety-one thousand, three hundred seventy-nine".