21213626 has 8 divisors (see below), whose sum is σ = 36366240. Its totient is φ = 9091548.

The previous prime is 21213623. The next prime is 21213631. The reversal of 21213626 is 62631212.

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

It is not an unprimeable number, because it can be changed into a prime (21213623) 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, 757616 + ... + 757643.

It is an arithmetic number, because the mean of its divisors is an integer number (4545780).

Almost surely, 2^21213626 is an apocalyptic number.

21213626 is a deficient number, since it is larger than the sum of its proper divisors (15152614).

21213626 is a wasteful number, since it uses less digits than its factorization.

21213626 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1515268.

The product of its digits is 864, while the sum is 23.

The square root of 21213626 is about 4605.8252246476. The cubic root of 21213626 is about 276.8247837326.

Adding to 21213626 its reverse (62631212), we get a palindrome (83844838).

The spelling of 21213626 in words is "twenty-one million, two hundred thirteen thousand, six hundred twenty-six".