23156209 has 2 divisors, whose sum is σ = 23156210. Its totient is φ = 23156208.

The previous prime is 23156207. The next prime is 23156219. The reversal of 23156209 is 90265132.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18249984 + 4906225 = 4272^2 + 2215^2 .

It is a cyclic number.

It is not a de Polignac number, because 23156209 - 2¹ = 23156207 is a prime.

It is a super-3 number, since 3×23156209³ (a number of 23 digits) contains 333 as substring.

Together with 23156207, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (23156201) 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, 11578104 + 11578105.

It is an arithmetic number, because the mean of its divisors is an integer number (11578105).

Almost surely, 2^23156209 is an apocalyptic number.

It is an amenable number.

23156209 is a deficient number, since it is larger than the sum of its proper divisors (1).

23156209 is an equidigital number, since it uses as much as digits as its factorization.

23156209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 23156209 is about 4812.0898786286. The cubic root of 23156209 is about 285.0290685442.

The spelling of 23156209 in words is "twenty-three million, one hundred fifty-six thousand, two hundred nine".