23421440 has 80 divisors (see below), whose sum is σ = 64228032. Its totient is φ = 8024064.

The previous prime is 23421421. The next prime is 23421443. The reversal of 23421440 is 4412432.

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 not an unprimeable number, because it can be changed into a prime (23421443) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17267 + ... + 18573.

Almost surely, 2^23421440 is an apocalyptic number.

23421440 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 23421440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32114016).

23421440 is an abundant number, since it is smaller than the sum of its proper divisors (40806592).

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

23421440 is an equidigital number, since it uses as much as digits as its factorization.

23421440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1337 (or 1321 counting only the distinct ones).

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

The square root of 23421440 is about 4839.5702288530. The cubic root of 23421440 is about 286.1131799755.

Adding to 23421440 its reverse (4412432), we get a palindrome (27833872).

The spelling of 23421440 in words is "twenty-three million, four hundred twenty-one thousand, four hundred forty".