23121643 has 2 divisors, whose sum is σ = 23121644. Its totient is φ = 23121642.

The previous prime is 23121617. The next prime is 23121661. The reversal of 23121643 is 34612132.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-23121643 is a prime.

It is a super-2 number, since 2×23121643² = 1069220750038898, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (23121673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11560821 + 11560822.

It is an arithmetic number, because the mean of its divisors is an integer number (11560822).

Almost surely, 2^23121643 is an apocalyptic number.

23121643 is a deficient number, since it is larger than the sum of its proper divisors (1).

23121643 is an equidigital number, since it uses as much as digits as its factorization.

23121643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 864, while the sum is 22.

The square root of 23121643 is about 4808.4969585100. The cubic root of 23121643 is about 284.8871739716.

Adding to 23121643 its reverse (34612132), we get a palindrome (57733775).

The spelling of 23121643 in words is "twenty-three million, one hundred twenty-one thousand, six hundred forty-three".