20109520 has 40 divisors (see below), whose sum is σ = 47057256. Its totient is φ = 7991808.

The previous prime is 20109517. The next prime is 20109539. The reversal of 20109520 is 2590102.

It can be written as a sum of positive squares in 4 ways, for example, as 11861136 + 8248384 = 3444^2 + 2872^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 13114 + ... + 14566.

Almost surely, 2^20109520 is an apocalyptic number.

20109520 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 20109520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23528628).

20109520 is an abundant number, since it is smaller than the sum of its proper divisors (26947736).

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

20109520 is a wasteful number, since it uses less digits than its factorization.

20109520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1639 (or 1633 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 20109520 is about 4484.3639459794. The cubic root of 20109520 is about 271.9363316955.

Adding to 20109520 its reverse (2590102), we get a palindrome (22699622).

It can be divided in two parts, 20 and 109520, that multiplied together give a square (2190400 = 1480²).

The spelling of 20109520 in words is "twenty million, one hundred nine thousand, five hundred twenty".