21426829 has 4 divisors (see below), whose sum is σ = 21463200. Its totient is φ = 21390460.

The previous prime is 21426827. The next prime is 21426841. The reversal of 21426829 is 92862412.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21426829 - 2¹ = 21426827 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21426794 and 21426803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21426827) 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 in 3 ways as a sum of consecutive naturals, for example, 17287 + ... + 18484.

It is an arithmetic number, because the mean of its divisors is an integer number (5365800).

Almost surely, 2^21426829 is an apocalyptic number.

It is an amenable number.

21426829 is a deficient number, since it is larger than the sum of its proper divisors (36371).

21426829 is an equidigital number, since it uses as much as digits as its factorization.

21426829 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36370.

The product of its digits is 13824, while the sum is 34.

The square root of 21426829 is about 4628.9122912408. The cubic root of 21426829 is about 277.7490835012.

The spelling of 21426829 in words is "twenty-one million, four hundred twenty-six thousand, eight hundred twenty-nine".