22431240 has 96 divisors (see below), whose sum is σ = 78525720. Its totient is φ = 5520384.

The previous prime is 22431209. The next prime is 22431263. The reversal of 22431240 is 4213422.

It can be written as a sum of positive squares in 4 ways, for example, as 18096516 + 4334724 = 4254^2 + 2082^2 .

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 23 ways as a sum of consecutive naturals, for example, 2284 + ... + 7076.

Almost surely, 2^22431240 is an apocalyptic number.

22431240 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 22431240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39262860).

22431240 is an abundant number, since it is smaller than the sum of its proper divisors (56094480).

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

22431240 is a wasteful number, since it uses less digits than its factorization.

22431240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4823 (or 4816 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 22431240 is about 4736.1630039516. The cubic root of 22431240 is about 282.0229346067.

Adding to 22431240 its reverse (4213422), we get a palindrome (26644662).

The spelling of 22431240 in words is "twenty-two million, four hundred thirty-one thousand, two hundred forty".