22431440 has 80 divisors (see below), whose sum is σ = 55496448. Its totient is φ = 8414208.

The previous prime is 22431439. The next prime is 22431473. The reversal of 22431440 is 4413422.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 134237 + ... + 134403.

Almost surely, 2^22431440 is an apocalyptic number.

22431440 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 22431440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27748224).

22431440 is an abundant number, since it is smaller than the sum of its proper divisors (33065008).

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

22431440 is a wasteful number, since it uses less digits than its factorization.

22431440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276 (or 270 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

The square root of 22431440 is about 4736.1841180427. The cubic root of 22431440 is about 282.0237727892.

Adding to 22431440 its reverse (4413422), we get a palindrome (26844862).

The spelling of 22431440 in words is "twenty-two million, four hundred thirty-one thousand, four hundred forty".