21438826 has 8 divisors (see below), whose sum is σ = 32325444. Its totient is φ = 10663680.

The previous prime is 21438793. The next prime is 21438827. The reversal of 21438826 is 62883412.

It can be written as a sum of positive squares in 2 ways, for example, as 18020025 + 3418801 = 4245^2 + 1849^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21438791 and 21438800.

It is not an unprimeable number, because it can be changed into a prime (21438827) 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 in 3 ways as a sum of consecutive naturals, for example, 27385 + ... + 28156.

Almost surely, 2^21438826 is an apocalyptic number.

21438826 is a deficient number, since it is larger than the sum of its proper divisors (10886618).

21438826 is a wasteful number, since it uses less digits than its factorization.

21438826 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55736.

The product of its digits is 18432, while the sum is 34.

The square root of 21438826 is about 4630.2079866892. The cubic root of 21438826 is about 277.8009115785.

The spelling of 21438826 in words is "twenty-one million, four hundred thirty-eight thousand, eight hundred twenty-six".