22521240 has 192 divisors, whose sum is σ = 87010560. Its totient is φ = 5132160.

The previous prime is 22521229. The next prime is 22521263. The reversal of 22521240 is 4212522.

It is a super-2 number, since 2×22521240² = 1014412502275200, which contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 67875 + ... + 68205.

It is an arithmetic number, because the mean of its divisors is an integer number (453180).

Almost surely, 2^22521240 is an apocalyptic number.

22521240 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 22521240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43505280).

22521240 is an abundant number, since it is smaller than the sum of its proper divisors (64489320).

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

22521240 is a wasteful number, since it uses less digits than its factorization.

22521240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 364 (or 348 counting only the distinct ones).

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

The square root of 22521240 is about 4745.6548547066. The cubic root of 22521240 is about 282.3996145270.

Adding to 22521240 its reverse (4212522), we get a palindrome (26733762).

The spelling of 22521240 in words is "twenty-two million, five hundred twenty-one thousand, two hundred forty".