21140423 has 2 divisors, whose sum is σ = 21140424. Its totient is φ = 21140422.

The previous prime is 21140389. The next prime is 21140501. The reversal of 21140423 is 32404112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21140423 - 2⁸ = 21140167 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21140123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10570211 + 10570212.

It is an arithmetic number, because the mean of its divisors is an integer number (10570212).

Almost surely, 2^21140423 is an apocalyptic number.

21140423 is a deficient number, since it is larger than the sum of its proper divisors (1).

21140423 is an equidigital number, since it uses as much as digits as its factorization.

21140423 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 21140423 is about 4597.8715728041. The cubic root of 21140423 is about 276.5059987123.

Adding to 21140423 its reverse (32404112), we get a palindrome (53544535).

The spelling of 21140423 in words is "twenty-one million, one hundred forty thousand, four hundred twenty-three".