20906624 has 32 divisors (see below), whose sum is σ = 41888340. Its totient is φ = 10393600.

The previous prime is 20906581. The next prime is 20906629. The reversal of 20906624 is 42660902.

It can be written as a sum of positive squares in 2 ways, for example, as 20866624 + 40000 = 4568^2 + 200^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is not an unprimeable number, because it can be changed into a prime (20906629) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29474 + ... + 30174.

Almost surely, 2^20906624 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20906624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20944170).

20906624 is an abundant number, since it is smaller than the sum of its proper divisors (20981716).

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

20906624 is an equidigital number, since it uses as much as digits as its factorization.

20906624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 948 (or 936 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 20906624 is about 4572.3761874981. The cubic root of 20906624 is about 275.4828937022.

The spelling of 20906624 in words is "twenty million, nine hundred six thousand, six hundred twenty-four".