21605627 has 2 divisors, whose sum is σ = 21605628. Its totient is φ = 21605626.

The previous prime is 21605611. The next prime is 21605659. The reversal of 21605627 is 72650612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21605627 - 2⁴ = 21605611 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21605627.

It is not a weakly prime, because it can be changed into another prime (21605677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10802813 + 10802814.

It is an arithmetic number, because the mean of its divisors is an integer number (10802814).

Almost surely, 2^21605627 is an apocalyptic number.

21605627 is a deficient number, since it is larger than the sum of its proper divisors (1).

21605627 is an equidigital number, since it uses as much as digits as its factorization.

21605627 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 21605627 is about 4648.1853448416. The cubic root of 21605627 is about 278.5195114544.

The spelling of 21605627 in words is "twenty-one million, six hundred five thousand, six hundred twenty-seven".