23121817 has 2 divisors, whose sum is σ = 23121818. Its totient is φ = 23121816.

The previous prime is 23121797. The next prime is 23121821. The reversal of 23121817 is 71812132.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21261321 + 1860496 = 4611^2 + 1364^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-23121817 is a prime.

It is equal to p_1455424 and since 23121817 and 1455424 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 23121791 and 23121800.

It is not a weakly prime, because it can be changed into another prime (23121517) 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, 11560908 + 11560909.

It is an arithmetic number, because the mean of its divisors is an integer number (11560909).

Almost surely, 2^23121817 is an apocalyptic number.

It is an amenable number.

23121817 is a deficient number, since it is larger than the sum of its proper divisors (1).

23121817 is an equidigital number, since it uses as much as digits as its factorization.

23121817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 672, while the sum is 25.

The square root of 23121817 is about 4808.5150514478. The cubic root of 23121817 is about 284.8878886014.

Adding to 23121817 its reverse (71812132), we get a palindrome (94933949).

The spelling of 23121817 in words is "twenty-three million, one hundred twenty-one thousand, eight hundred seventeen".