123309491 has 2 divisors, whose sum is σ = 123309492. Its totient is φ = 123309490.

The previous prime is 123309481. The next prime is 123309497. The reversal of 123309491 is 194903321.

It is a strong prime.

It is an emirp because it is prime and its reverse (194903321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 123309491 - 2¹⁰ = 123308467 is a prime.

It is equal to p_7019339 and since 123309491 and 7019339 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (123309497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61654745 + 61654746.

It is an arithmetic number, because the mean of its divisors is an integer number (61654746).

Almost surely, 2^123309491 is an apocalyptic number.

123309491 is a deficient number, since it is larger than the sum of its proper divisors (1).

123309491 is an equidigital number, since it uses as much as digits as its factorization.

123309491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5832, while the sum is 32.

The square root of 123309491 is about 11104.4806722332. The cubic root of 123309491 is about 497.7357498201.

The spelling of 123309491 in words is "one hundred twenty-three million, three hundred nine thousand, four hundred ninety-one".