21413423 has 2 divisors, whose sum is σ = 21413424. Its totient is φ = 21413422.

The previous prime is 21413393. The next prime is 21413443. The reversal of 21413423 is 32431412.

It is an a-pointer prime, because the next prime (21413443) can be obtained adding 21413423 to its sum of digits (20).

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21413423 - 2⁸ = 21413167 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21413395 and 21413404.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21413443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10706711 + 10706712.

It is an arithmetic number, because the mean of its divisors is an integer number (10706712).

Almost surely, 2^21413423 is an apocalyptic number.

21413423 is a deficient number, since it is larger than the sum of its proper divisors (1).

21413423 is an equidigital number, since it uses as much as digits as its factorization.

21413423 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 576, while the sum is 20.

The square root of 21413423 is about 4627.4639922964. The cubic root of 21413423 is about 277.6911455295.

Adding to 21413423 its reverse (32431412), we get a palindrome (53844835).

The spelling of 21413423 in words is "twenty-one million, four hundred thirteen thousand, four hundred twenty-three".