23709240 has 128 divisors (see below), whose sum is σ = 81864000. Its totient is φ = 6096384.

The previous prime is 23709239. The next prime is 23709241. The reversal of 23709240 is 4290732.

It is an interprime number because it is at equal distance from previous prime (23709239) and next prime (23709241).

It is a super-2 number, since 2×23709240² = 1124256122755200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23709241) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 30942 + ... + 31698.

Almost surely, 2^23709240 is an apocalyptic number.

23709240 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 23709240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40932000).

23709240 is an abundant number, since it is smaller than the sum of its proper divisors (58154760).

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

23709240 is a wasteful number, since it uses less digits than its factorization.

23709240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 806 (or 796 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 27.

The square root of 23709240 is about 4869.2134888501. The cubic root of 23709240 is about 287.2803211590.

Adding to 23709240 its reverse (4290732), we get a palindrome (27999972).

The spelling of 23709240 in words is "twenty-three million, seven hundred nine thousand, two hundred forty".