23257440 has 144 divisors (see below), whose sum is σ = 82083456. Its totient is φ = 5990400.

The previous prime is 23257397. The next prime is 23257441. The reversal of 23257440 is 4475232.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23257441) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 44380 + ... + 44900.

It is an arithmetic number, because the mean of its divisors is an integer number (570024).

Almost surely, 2^23257440 is an apocalyptic number.

23257440 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 23257440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41041728).

23257440 is an abundant number, since it is smaller than the sum of its proper divisors (58826016).

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

23257440 is a wasteful number, since it uses less digits than its factorization.

23257440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 573 (or 562 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 27.

The square root of 23257440 is about 4822.5968108479. The cubic root of 23257440 is about 285.4438145156.

The spelling of 23257440 in words is "twenty-three million, two hundred fifty-seven thousand, four hundred forty".