123507409 has 2 divisors, whose sum is σ = 123507410. Its totient is φ = 123507408.

The previous prime is 123507407. The next prime is 123507421. The reversal of 123507409 is 904705321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 121616784 + 1890625 = 11028^2 + 1375^2 .

It is a cyclic number.

It is not a de Polignac number, because 123507409 - 2¹ = 123507407 is a prime.

Together with 123507407, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (123507407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61753704 + 61753705.

It is an arithmetic number, because the mean of its divisors is an integer number (61753705).

Almost surely, 2^123507409 is an apocalyptic number.

It is an amenable number.

123507409 is a deficient number, since it is larger than the sum of its proper divisors (1).

123507409 is an equidigital number, since it uses as much as digits as its factorization.

123507409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7560, while the sum is 31.

The square root of 123507409 is about 11113.3887271165. The cubic root of 123507409 is about 498.0019045319.

The spelling of 123507409 in words is "one hundred twenty-three million, five hundred seven thousand, four hundred nine".