23640240 has 80 divisors (see below), whose sum is σ = 78932448. Its totient is φ = 5818368.

The previous prime is 23640233. The next prime is 23640241. The reversal of 23640240 is 4204632.

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

It is not an unprimeable number, because it can be changed into a prime (23640241) by changing a digit.

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, 669 + ... + 6908.

Almost surely, 2^23640240 is an apocalyptic number.

23640240 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 23640240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39466224).

23640240 is an abundant number, since it is smaller than the sum of its proper divisors (55292208).

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

23640240 is a wasteful number, since it uses less digits than its factorization.

23640240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7606 (or 7600 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 21.

The square root of 23640240 is about 4862.1229930967. The cubic root of 23640240 is about 287.0013637752.

Adding to 23640240 its reverse (4204632), we get a palindrome (27844872).

The spelling of 23640240 in words is "twenty-three million, six hundred forty thousand, two hundred forty".