21746638 has 16 divisors (see below), whose sum is σ = 36041760. Its totient is φ = 9788416.

The previous prime is 21746629. The next prime is 21746651. The reversal of 21746638 is 83664712.

It is a junction number, because it is equal to n+sod(n) for n = 21746597 and 21746606.

It is a congruent number.

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, 13123 + ... + 14686.

It is an arithmetic number, because the mean of its divisors is an integer number (2252610).

Almost surely, 2^21746638 is an apocalyptic number.

21746638 is a deficient number, since it is larger than the sum of its proper divisors (14295122).

21746638 is a wasteful number, since it uses less digits than its factorization.

21746638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27851.

The product of its digits is 48384, while the sum is 37.

The square root of 21746638 is about 4663.3290683802. The cubic root of 21746638 is about 279.1241252569.

The spelling of 21746638 in words is "twenty-one million, seven hundred forty-six thousand, six hundred thirty-eight".