23205440 has 56 divisors (see below), whose sum is σ = 55790592. Its totient is φ = 9192960.

The previous prime is 23205439. The next prime is 23205443. The reversal of 23205440 is 4450232.

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

It is not an unprimeable number, because it can be changed into a prime (23205443) 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, 40355 + ... + 40925.

Almost surely, 2^23205440 is an apocalyptic number.

23205440 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 23205440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27895296).

23205440 is an abundant number, since it is smaller than the sum of its proper divisors (32585152).

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

23205440 is a wasteful number, since it uses less digits than its factorization.

23205440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 715 (or 705 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 20.

The square root of 23205440 is about 4817.2025076802. The cubic root of 23205440 is about 285.2309198551.

Adding to 23205440 its reverse (4450232), we get a palindrome (27655672).

The spelling of 23205440 in words is "twenty-three million, two hundred five thousand, four hundred forty".