20866624 has 21 divisors (see below), whose sum is σ = 41479851. Its totient is φ = 10415040.

The previous prime is 20866621. The next prime is 20866639. The reversal of 20866624 is 42666802.

The square root of 20866624 is 4568.

It is a perfect power (a square), and thus also a powerful number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20866624.

It is not an unprimeable number, because it can be changed into a prime (20866621) by changing a digit.

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 2 ways as a sum of consecutive naturals, for example, 36259 + ... + 36829.

It is an arithmetic number, because the mean of its divisors is an integer number (1975231).

Almost surely, 2^20866624 is an apocalyptic number.

20866624 is the 4568-th square number.

It is an amenable number.

20866624 is a deficient number, since it is larger than the sum of its proper divisors (20613227).

20866624 is an frugal number, since it uses more digits than its factorization.

20866624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1154 (or 573 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 34.

The cubic root of 20866624 is about 275.3070905553.

The spelling of 20866624 in words is "twenty million, eight hundred sixty-six thousand, six hundred twenty-four".