21818626 has 8 divisors (see below), whose sum is σ = 33052284. Its totient is φ = 10801200.

The previous prime is 21818623. The next prime is 21818627. The reversal of 21818626 is 62681812.

It can be written as a sum of positive squares in 2 ways, for example, as 18020025 + 3798601 = 4245^2 + 1949^2 .

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 = 21818591 and 21818600.

It is not an unprimeable number, because it can be changed into a prime (21818623) 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, 53805 + ... + 54208.

Almost surely, 2^21818626 is an apocalyptic number.

21818626 is a deficient number, since it is larger than the sum of its proper divisors (11233658).

21818626 is a wasteful number, since it uses less digits than its factorization.

21818626 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108116.

The product of its digits is 9216, while the sum is 34.

The square root of 21818626 is about 4671.0412115502. The cubic root of 21818626 is about 279.4317813376.

The spelling of 21818626 in words is "twenty-one million, eight hundred eighteen thousand, six hundred twenty-six".