21129263 has 2 divisors, whose sum is σ = 21129264. Its totient is φ = 21129262.

The previous prime is 21129239. The next prime is 21129287. The reversal of 21129263 is 36292112.

It is a balanced prime because it is at equal distance from previous prime (21129239) and next prime (21129287).

It is a cyclic number.

It is not a de Polignac number, because 21129263 - 2¹⁴ = 21112879 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21129293) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10564631 + 10564632.

It is an arithmetic number, because the mean of its divisors is an integer number (10564632).

Almost surely, 2^21129263 is an apocalyptic number.

21129263 is a deficient number, since it is larger than the sum of its proper divisors (1).

21129263 is an equidigital number, since it uses as much as digits as its factorization.

21129263 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1296, while the sum is 26.

The square root of 21129263 is about 4596.6578075815. The cubic root of 21129263 is about 276.4573344368.

The spelling of 21129263 in words is "twenty-one million, one hundred twenty-nine thousand, two hundred sixty-three".