123928639 has 2 divisors, whose sum is σ = 123928640. Its totient is φ = 123928638.

The previous prime is 123928619. The next prime is 123928661. The reversal of 123928639 is 936829321.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 123928639 - 2²¹ = 121831487 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 123928595 and 123928604.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123928619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61964319 + 61964320.

It is an arithmetic number, because the mean of its divisors is an integer number (61964320).

Almost surely, 2^123928639 is an apocalyptic number.

123928639 is a deficient number, since it is larger than the sum of its proper divisors (1).

123928639 is an equidigital number, since it uses as much as digits as its factorization.

123928639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 139968, while the sum is 43.

The square root of 123928639 is about 11132.3240610395. The cubic root of 123928639 is about 498.5674180044.

The spelling of 123928639 in words is "one hundred twenty-three million, nine hundred twenty-eight thousand, six hundred thirty-nine".