20405484 has 54 divisors (see below), whose sum is σ = 56518644. Its totient is φ = 6156240.

The previous prime is 20405479. The next prime is 20405501. The reversal of 20405484 is 48450402.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 89779 + ... + 90005.

Almost surely, 2^20405484 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 20405484, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28259322).

20405484 is an abundant number, since it is smaller than the sum of its proper divisors (36113160).

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

20405484 is a wasteful number, since it uses less digits than its factorization.

20405484 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 475 (or 243 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 27.

The square root of 20405484 is about 4517.2429644641. The cubic root of 20405484 is about 273.2639238128.

Adding to 20405484 its reverse (48450402), we get a palindrome (68855886).

It can be divided in two parts, 20 and 405484, that added together give a palindrome (405504).

The spelling of 20405484 in words is "twenty million, four hundred five thousand, four hundred eighty-four".