20605424 has 80 divisors (see below), whose sum is σ = 50234880. Its totient is φ = 7983360.

The previous prime is 20605397. The next prime is 20605463. The reversal of 20605424 is 42450602.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a self number, because there is not a number n which added to its sum of digits gives 20605424.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48734 + ... + 49154.

It is an arithmetic number, because the mean of its divisors is an integer number (627936).

Almost surely, 2^20605424 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 20605424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25117440).

20605424 is an abundant number, since it is smaller than the sum of its proper divisors (29629456).

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

20605424 is a wasteful number, since it uses less digits than its factorization.

20605424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 478 (or 472 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 23.

The square root of 20605424 is about 4539.3197728294. The cubic root of 20605424 is about 274.1535360573.

The spelling of 20605424 in words is "twenty million, six hundred five thousand, four hundred twenty-four".