23651209 has 2 divisors, whose sum is σ = 23651210. Its totient is φ = 23651208.

The previous prime is 23651207. The next prime is 23651213. The reversal of 23651209 is 90215632.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23011209 + 640000 = 4797^2 + 800^2 .

It is a cyclic number.

It is not a de Polignac number, because 23651209 - 2¹ = 23651207 is a prime.

Together with 23651207, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (23651207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11825604 + 11825605.

It is an arithmetic number, because the mean of its divisors is an integer number (11825605).

Almost surely, 2^23651209 is an apocalyptic number.

It is an amenable number.

23651209 is a deficient number, since it is larger than the sum of its proper divisors (1).

23651209 is an equidigital number, since it uses as much as digits as its factorization.

23651209 is an evil number, because the sum of its binary digits is even.

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

The square root of 23651209 is about 4863.2508674754. The cubic root of 23651209 is about 287.0457461670.

The spelling of 23651209 in words is "twenty-three million, six hundred fifty-one thousand, two hundred nine".