123728791 has 2 divisors, whose sum is σ = 123728792. Its totient is φ = 123728790.

The previous prime is 123728783. The next prime is 123728887. The reversal of 123728791 is 197827321.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (197827321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 123728791 - 2³ = 123728783 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123728711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61864395 + 61864396.

It is an arithmetic number, because the mean of its divisors is an integer number (61864396).

Almost surely, 2^123728791 is an apocalyptic number.

123728791 is a deficient number, since it is larger than the sum of its proper divisors (1).

123728791 is an equidigital number, since it uses as much as digits as its factorization.

123728791 is an evil number, because the sum of its binary digits is even.

The product of its digits is 42336, while the sum is 40.

The square root of 123728791 is about 11123.3444161367. The cubic root of 123728791 is about 498.2992763035.

The spelling of 123728791 in words is "one hundred twenty-three million, seven hundred twenty-eight thousand, seven hundred ninety-one".