22215240 has 96 divisors (see below), whose sum is σ = 75366720. Its totient is φ = 5664384.

The previous prime is 22215229. The next prime is 22215241. The reversal of 22215240 is 4251222.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22215241) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6939 + ... + 9621.

It is an arithmetic number, because the mean of its divisors is an integer number (785070).

Almost surely, 2^22215240 is an apocalyptic number.

22215240 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 22215240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37683360).

22215240 is an abundant number, since it is smaller than the sum of its proper divisors (53151480).

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

22215240 is a wasteful number, since it uses less digits than its factorization.

22215240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2723 (or 2716 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 18.

The square root of 22215240 is about 4713.3045732267. The cubic root of 22215240 is about 281.1147735113.

Adding to 22215240 its reverse (4251222), we get a palindrome (26466462).

The spelling of 22215240 in words is "twenty-two million, two hundred fifteen thousand, two hundred forty".