20509396 has 12 divisors (see below), whose sum is σ = 36861748. Its totient is φ = 9977472.

The previous prime is 20509373. The next prime is 20509421. The reversal of 20509396 is 69390502.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 15713296 + 4796100 = 3964^2 + 2190^2 .

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 3 ways as a sum of consecutive naturals, for example, 69141 + ... + 69436.

Almost surely, 2^20509396 is an apocalyptic number.

It is an amenable number.

20509396 is a deficient number, since it is larger than the sum of its proper divisors (16352352).

20509396 is a wasteful number, since it uses less digits than its factorization.

20509396 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138618 (or 138616 counting only the distinct ones).

The product of its (nonzero) digits is 14580, while the sum is 34.

The square root of 20509396 is about 4528.7300648195. The cubic root of 20509396 is about 273.7269911091.

Adding to 20509396 its reverse (69390502), we get a palindrome (89899898).

The spelling of 20509396 in words is "twenty million, five hundred nine thousand, three hundred ninety-six".