123428391 has 16 divisors (see below), whose sum is σ = 170615808. Its totient is φ = 79286400.

The previous prime is 123428377. The next prime is 123428423. The reversal of 123428391 is 193824321.

It is not a de Polignac number, because 123428391 - 2¹⁸ = 123166247 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123428341) 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 in 15 ways as a sum of consecutive naturals, for example, 19660 + ... + 25166.

It is an arithmetic number, because the mean of its divisors is an integer number (10663488).

Almost surely, 2^123428391 is an apocalyptic number.

123428391 is a deficient number, since it is larger than the sum of its proper divisors (47187417).

123428391 is a wasteful number, since it uses less digits than its factorization.

123428391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5782.

The product of its digits is 10368, while the sum is 33.

The square root of 123428391 is about 11109.8330770539. The cubic root of 123428391 is about 497.8956774106.

The spelling of 123428391 in words is "one hundred twenty-three million, four hundred twenty-eight thousand, three hundred ninety-one".