20421120 has 80 divisors (see below), whose sum is σ = 65308320. Its totient is φ = 5443584.

The previous prime is 20421103. The next prime is 20421179. The reversal of 20421120 is 2112402.

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 (12).

It is a junction number, because it is equal to n+sod(n) for n = 20421096 and 20421105.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6351 + ... + 9009.

It is an arithmetic number, because the mean of its divisors is an integer number (816354).

Almost surely, 2^20421120 is an apocalyptic number.

20421120 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 20421120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32654160).

20421120 is an abundant number, since it is smaller than the sum of its proper divisors (44887200).

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

20421120 is an equidigital number, since it uses as much as digits as its factorization.

20421120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2685 (or 2669 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 20421120 is about 4518.9733347299. The cubic root of 20421120 is about 273.3337034829. Note that the first 3 decimals are identical.

Adding to 20421120 its reverse (2112402), we get a palindrome (22533522).

The spelling of 20421120 in words is "twenty million, four hundred twenty-one thousand, one hundred twenty".