20409456 has 20 divisors (see below), whose sum is σ = 52724552. Its totient is φ = 6803136.

The previous prime is 20409437. The next prime is 20409481. The reversal of 20409456 is 65490402.

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, 212551 + ... + 212646.

Almost surely, 2^20409456 is an apocalyptic number.

It is an amenable number.

20409456 is an abundant number, since it is smaller than the sum of its proper divisors (32315096).

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

20409456 is a wasteful number, since it uses less digits than its factorization.

20409456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 425208 (or 425202 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 20409456 is about 4517.6825917720. The cubic root of 20409456 is about 273.2816532606.

Adding to 20409456 its reverse (65490402), we get a palindrome (85899858).

The spelling of 20409456 in words is "twenty million, four hundred nine thousand, four hundred fifty-six".