21130423 has 2 divisors, whose sum is σ = 21130424. Its totient is φ = 21130422.

The previous prime is 21130409. The next prime is 21130453. The reversal of 21130423 is 32403112.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21130423 - 2²¹ = 19033271 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21130397 and 21130406.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21130453) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10565211 + 10565212.

It is an arithmetic number, because the mean of its divisors is an integer number (10565212).

Almost surely, 2^21130423 is an apocalyptic number.

21130423 is a deficient number, since it is larger than the sum of its proper divisors (1).

21130423 is an equidigital number, since it uses as much as digits as its factorization.

21130423 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 21130423 is about 4596.7839844831. The cubic root of 21130423 is about 276.4623935286.

Adding to 21130423 its reverse (32403112), we get a palindrome (53533535).

The spelling of 21130423 in words is "twenty-one million, one hundred thirty thousand, four hundred twenty-three".