20409360 has 80 divisors (see below), whose sum is σ = 63704256. Its totient is φ = 5405184.

The previous prime is 20409353. The next prime is 20409371. The reversal of 20409360 is 6390402.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 20409360.

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 15 ways as a sum of consecutive naturals, for example, 66327 + ... + 66633.

Almost surely, 2^20409360 is an apocalyptic number.

20409360 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20409360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31852128).

20409360 is an abundant number, since it is smaller than the sum of its proper divisors (43294896).

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

20409360 is a wasteful number, since it uses less digits than its factorization.

20409360 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 600 (or 594 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 24.

The square root of 20409360 is about 4517.6719668431. The cubic root of 20409360 is about 273.2812247814.

Adding to 20409360 its reverse (6390402), we get a palindrome (26799762).

The spelling of 20409360 in words is "twenty million, four hundred nine thousand, three hundred sixty".