20209536 has 96 divisors (see below), whose sum is σ = 59431320. Its totient is φ = 6589440.

The previous prime is 20209523. The next prime is 20209547. The reversal of 20209536 is 63590202.

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 60891 + ... + 61221.

Almost surely, 2^20209536 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 20209536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29715660).

20209536 is an abundant number, since it is smaller than the sum of its proper divisors (39221784).

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

20209536 is a wasteful number, since it uses less digits than its factorization.

20209536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 404 (or 389 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 27.

The square root of 20209536 is about 4495.5017517514. The cubic root of 20209536 is about 272.3864173268.

Adding to 20209536 its reverse (63590202), we get a palindrome (83799738).

The spelling of 20209536 in words is "twenty million, two hundred nine thousand, five hundred thirty-six".