23440421 has 2 divisors, whose sum is σ = 23440422. Its totient is φ = 23440420.

The previous prime is 23440411. The next prime is 23440423. The reversal of 23440421 is 12404432.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14737921 + 8702500 = 3839^2 + 2950^2 .

It is a cyclic number.

It is not a de Polignac number, because 23440421 - 2¹⁰ = 23439397 is a prime.

Together with 23440423, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 23440393 and 23440402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23440423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11720210 + 11720211.

It is an arithmetic number, because the mean of its divisors is an integer number (11720211).

Almost surely, 2^23440421 is an apocalyptic number.

It is an amenable number.

23440421 is a deficient number, since it is larger than the sum of its proper divisors (1).

23440421 is an equidigital number, since it uses as much as digits as its factorization.

23440421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 768, while the sum is 20.

The square root of 23440421 is about 4841.5308529431. The cubic root of 23440421 is about 286.1904488922.

Adding to 23440421 its reverse (12404432), we get a palindrome (35844853).

The spelling of 23440421 in words is "twenty-three million, four hundred forty thousand, four hundred twenty-one".