21886605 has 40 divisors (see below), whose sum is σ = 42261912. Its totient is φ = 10772352.

The previous prime is 21886603. The next prime is 21886607. The reversal of 21886605 is 50668812.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21886603) and next prime (21886607).

It can be written as a sum of positive squares in 4 ways, for example, as 236196 + 21650409 = 486^2 + 4653^2 .

It is not a de Polignac number, because 21886605 - 2¹ = 21886603 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21886605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21886603) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 3187 + ... + 7343.

Almost surely, 2^21886605 is an apocalyptic number.

It is an amenable number.

21886605 is a deficient number, since it is larger than the sum of its proper divisors (20375307).

21886605 is a wasteful number, since it uses less digits than its factorization.

21886605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4187 (or 4178 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 21886605 is about 4678.3121956535. The cubic root of 21886605 is about 279.7216834825.

The spelling of 21886605 in words is "twenty-one million, eight hundred eighty-six thousand, six hundred five".