20315520 has 96 divisors (see below), whose sum is σ = 70171920. Its totient is φ = 5415936.

The previous prime is 20315513. The next prime is 20315521. The reversal of 20315520 is 2551302.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 20315493 and 20315502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20315521) 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 11 ways as a sum of consecutive naturals, for example, 3997 + ... + 7523.

Almost surely, 2^20315520 is an apocalyptic number.

20315520 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 20315520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35085960).

20315520 is an abundant number, since it is smaller than the sum of its proper divisors (49856400).

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

20315520 is a wasteful number, since it uses less digits than its factorization.

20315520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3552 (or 3537 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 18.

The square root of 20315520 is about 4507.2741207963. The cubic root of 20315520 is about 272.8617421732.

Adding to 20315520 its reverse (2551302), we get a palindrome (22866822).

The spelling of 20315520 in words is "twenty million, three hundred fifteen thousand, five hundred twenty".