21636626 has 16 divisors (see below), whose sum is σ = 35773920. Its totient is φ = 9732480.

The previous prime is 21636619. The next prime is 21636647. The reversal of 21636626 is 62663612.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21636592 and 21636601.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2936 + ... + 7203.

It is an arithmetic number, because the mean of its divisors is an integer number (2235870).

Almost surely, 2^21636626 is an apocalyptic number.

21636626 is a deficient number, since it is larger than the sum of its proper divisors (14137294).

21636626 is a wasteful number, since it uses less digits than its factorization.

21636626 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10249.

The product of its digits is 15552, while the sum is 32.

The square root of 21636626 is about 4651.5186767334. The cubic root of 21636626 is about 278.6526511600.

The spelling of 21636626 in words is "twenty-one million, six hundred thirty-six thousand, six hundred twenty-six".