23121281 has 2 divisors, whose sum is σ = 23121282. Its totient is φ = 23121280.

The previous prime is 23121247. The next prime is 23121283. The reversal of 23121281 is 18212132.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14025025 + 9096256 = 3745^2 + 3016^2 .

It is a cyclic number.

It is not a de Polignac number, because 23121281 - 2¹⁴ = 23104897 is a prime.

It is a super-2 number, since 2×23121281² = 1069187270161922, which contains 22 as substring.

Together with 23121283, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (23121283) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11560640 + 11560641.

It is an arithmetic number, because the mean of its divisors is an integer number (11560641).

Almost surely, 2^23121281 is an apocalyptic number.

It is an amenable number.

23121281 is a deficient number, since it is larger than the sum of its proper divisors (1).

23121281 is an equidigital number, since it uses as much as digits as its factorization.

23121281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 192, while the sum is 20.

The square root of 23121281 is about 4808.4593166627. The cubic root of 23121281 is about 284.8856872016.

It can be divided in two parts, 231 and 21281, that added together give a palindrome (21512).

The spelling of 23121281 in words is "twenty-three million, one hundred twenty-one thousand, two hundred eighty-one".