20201520 has 80 divisors (see below), whose sum is σ = 64183392. Its totient is φ = 5253120.

The previous prime is 20201507. The next prime is 20201527. The reversal of 20201520 is 2510202.

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 = 20201496 and 20201505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20201527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8814 + ... + 10866.

Almost surely, 2^20201520 is an apocalyptic number.

20201520 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 20201520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32091696).

20201520 is an abundant number, since it is smaller than the sum of its proper divisors (43981872).

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

20201520 is a wasteful number, since it uses less digits than its factorization.

20201520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2110 (or 2104 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 12.

The square root of 20201520 is about 4494.6101054485. The cubic root of 20201520 is about 272.3503990454.

Adding to 20201520 its reverse (2510202), we get a palindrome (22711722).

The spelling of 20201520 in words is "twenty million, two hundred one thousand, five hundred twenty".