22251240 has 128 divisors (see below), whose sum is σ = 80956800. Its totient is φ = 5391360.

The previous prime is 22251239. The next prime is 22251263. The reversal of 22251240 is 4215222.

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

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10944 + ... + 12816.

It is an arithmetic number, because the mean of its divisors is an integer number (632475).

Almost surely, 2^22251240 is an apocalyptic number.

22251240 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 22251240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40478400).

22251240 is an abundant number, since it is smaller than the sum of its proper divisors (58705560).

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

22251240 is a wasteful number, since it uses less digits than its factorization.

22251240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1904 (or 1894 counting only the distinct ones).

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

The square root of 22251240 is about 4717.1220039342. The cubic root of 22251240 is about 281.2665412494.

Adding to 22251240 its reverse (4215222), we get a palindrome (26466462).

The spelling of 22251240 in words is "twenty-two million, two hundred fifty-one thousand, two hundred forty".