20403120 has 80 divisors (see below), whose sum is σ = 63781632. Its totient is φ = 5395200.

The previous prime is 20403083. The next prime is 20403121. The reversal of 20403120 is 2130402.

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 = 20403096 and 20403105.

It is not an unprimeable number, because it can be changed into a prime (20403121) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 35959 + ... + 36521.

Almost surely, 2^20403120 is an apocalyptic number.

20403120 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 20403120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31890816).

20403120 is an abundant number, since it is smaller than the sum of its proper divisors (43378512).

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

20403120 is a wasteful number, since it uses less digits than its factorization.

20403120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 730 (or 724 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 12.

The square root of 20403120 is about 4516.9812928548. The cubic root of 20403120 is about 273.2533707532.

Adding to 20403120 its reverse (2130402), we get a palindrome (22533522).

The spelling of 20403120 in words is "twenty million, four hundred three thousand, one hundred twenty".