20506424 has 8 divisors (see below), whose sum is σ = 38449560. Its totient is φ = 10253208.

The previous prime is 20506417. The next prime is 20506427. The reversal of 20506424 is 42460502.

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 20506424.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20506427) by changing a digit.

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 as a sum of consecutive naturals, namely, 1281644 + ... + 1281659.

It is an arithmetic number, because the mean of its divisors is an integer number (4806195).

Almost surely, 2^20506424 is an apocalyptic number.

It is an amenable number.

20506424 is a deficient number, since it is larger than the sum of its proper divisors (17943136).

20506424 is a wasteful number, since it uses less digits than its factorization.

20506424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2563309 (or 2563305 counting only the distinct ones).

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

The square root of 20506424 is about 4528.4019256245. The cubic root of 20506424 is about 273.7137686180.

Adding to 20506424 its reverse (42460502), we get a palindrome (62966926).

The spelling of 20506424 in words is "twenty million, five hundred six thousand, four hundred twenty-four".