123865619 has 2 divisors, whose sum is σ = 123865620. Its totient is φ = 123865618.

The previous prime is 123865607. The next prime is 123865657. The reversal of 123865619 is 916568321.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 123865619 - 2²⁰ = 122817043 is a prime.

It is a super-2 number, since 2×123865619² = 30685383140506322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (123865919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61932809 + 61932810.

It is an arithmetic number, because the mean of its divisors is an integer number (61932810).

Almost surely, 2^123865619 is an apocalyptic number.

123865619 is a deficient number, since it is larger than the sum of its proper divisors (1).

123865619 is an equidigital number, since it uses as much as digits as its factorization.

123865619 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 77760, while the sum is 41.

The square root of 123865619 is about 11129.4932049937. The cubic root of 123865619 is about 498.4828934310.

The spelling of 123865619 in words is "one hundred twenty-three million, eight hundred sixty-five thousand, six hundred nineteen".