23420921 has 2 divisors, whose sum is σ = 23420922. Its totient is φ = 23420920.

The previous prime is 23420879. The next prime is 23420933. The reversal of 23420921 is 12902432.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16974400 + 6446521 = 4120^2 + 2539^2 .

It is a cyclic number.

It is not a de Polignac number, because 23420921 - 2²² = 19226617 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (23420021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11710460 + 11710461.

It is an arithmetic number, because the mean of its divisors is an integer number (11710461).

Almost surely, 2^23420921 is an apocalyptic number.

It is an amenable number.

23420921 is a deficient number, since it is larger than the sum of its proper divisors (1).

23420921 is an equidigital number, since it uses as much as digits as its factorization.

23420921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 23420921 is about 4839.5166080922. The cubic root of 23420921 is about 286.1110666150. Note that the first 3 decimals are identical.

The spelling of 23420921 in words is "twenty-three million, four hundred twenty thousand, nine hundred twenty-one".