22131520 has 112 divisors (see below), whose sum is σ = 57351168. Its totient is φ = 8110080.

The previous prime is 22131509. The next prime is 22131521. The reversal of 22131520 is 2513122.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a junction number, because it is equal to n+sod(n) for n = 22131494 and 22131503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22131521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 228112 + ... + 228208.

It is an arithmetic number, because the mean of its divisors is an integer number (512064).

Almost surely, 2^22131520 is an apocalyptic number.

22131520 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 22131520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28675584).

22131520 is an abundant number, since it is smaller than the sum of its proper divisors (35219648).

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

22131520 is a wasteful number, since it uses less digits than its factorization.

22131520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168 (or 158 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 22131520 is about 4704.4149476848. The cubic root of 22131520 is about 280.7611940865.

Adding to 22131520 its reverse (2513122), we get a palindrome (24644642).

The spelling of 22131520 in words is "twenty-two million, one hundred thirty-one thousand, five hundred twenty".