123505979 has 2 divisors, whose sum is σ = 123505980. Its totient is φ = 123505978.

The previous prime is 123505937. The next prime is 123505997. The reversal of 123505979 is 979505321.

Together with next prime (123505997) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123505979 is a prime.

It is not a weakly prime, because it can be changed into another prime (123505379) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61752989 + 61752990.

It is an arithmetic number, because the mean of its divisors is an integer number (61752990).

Almost surely, 2^123505979 is an apocalyptic number.

123505979 is a deficient number, since it is larger than the sum of its proper divisors (1).

123505979 is an equidigital number, since it uses as much as digits as its factorization.

123505979 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 85050, while the sum is 41.

The square root of 123505979 is about 11113.3243901184. The cubic root of 123505979 is about 497.9999825272. Note that the first 4 decimals are identical.

The spelling of 123505979 in words is "one hundred twenty-three million, five hundred five thousand, nine hundred seventy-nine".