21866634 has 24 divisors (see below), whose sum is σ = 48273732. Its totient is φ = 7151040.

The previous prime is 21866597. The next prime is 21866671. The reversal of 21866634 is 43666812.

It is an interprime number because it is at equal distance from previous prime (21866597) and next prime (21866671).

It can be written as a sum of positive squares in 2 ways, for example, as 21650409 + 216225 = 4653^2 + 465^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10507 + ... + 12414.

Almost surely, 2^21866634 is an apocalyptic number.

21866634 is an abundant number, since it is smaller than the sum of its proper divisors (26407098).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21866634 is a wasteful number, since it uses less digits than its factorization.

21866634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22982 (or 22979 counting only the distinct ones).

The product of its digits is 41472, while the sum is 36.

The square root of 21866634 is about 4676.1772849198. The cubic root of 21866634 is about 279.6365778250.

It can be divided in two parts, 21866 and 634, that added together give a square (22500 = 150²).

The spelling of 21866634 in words is "twenty-one million, eight hundred sixty-six thousand, six hundred thirty-four".