21129343 has 2 divisors, whose sum is σ = 21129344. Its totient is φ = 21129342.

The previous prime is 21129337. The next prime is 21129359. The reversal of 21129343 is 34392112.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21129343 is a prime.

It is a super-2 number, since 2×21129343² = 892898271223298, which contains 22 as substring.

It is equal to p_1337641 and since 21129343 and 1337641 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21129643) 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, 10564671 + 10564672.

It is an arithmetic number, because the mean of its divisors is an integer number (10564672).

Almost surely, 2^21129343 is an apocalyptic number.

21129343 is a deficient number, since it is larger than the sum of its proper divisors (1).

21129343 is an equidigital number, since it uses as much as digits as its factorization.

21129343 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1296, while the sum is 25.

The square root of 21129343 is about 4596.6665095480. Note that the first 3 decimals coincide. The cubic root of 21129343 is about 276.4576833457.

The spelling of 21129343 in words is "twenty-one million, one hundred twenty-nine thousand, three hundred forty-three".