23646640 has 80 divisors (see below), whose sum is σ = 59281920. Its totient is φ = 8743680.

The previous prime is 23646619. The next prime is 23646641. The reversal of 23646640 is 4664632.

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 (23646641) 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, 71275 + ... + 71605.

It is an arithmetic number, because the mean of its divisors is an integer number (741024).

Almost surely, 2^23646640 is an apocalyptic number.

23646640 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 23646640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29640960).

23646640 is an abundant number, since it is smaller than the sum of its proper divisors (35635280).

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

23646640 is a wasteful number, since it uses less digits than its factorization.

23646640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 410 (or 404 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 31.

The square root of 23646640 is about 4862.7810972735. The cubic root of 23646640 is about 287.0272609037.

The spelling of 23646640 in words is "twenty-three million, six hundred forty-six thousand, six hundred forty".