23431540 has 48 divisors (see below), whose sum is σ = 54452160. Its totient is φ = 8398080.

The previous prime is 23431531. The next prime is 23431547. The reversal of 23431540 is 4513432.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23431547) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15331 + ... + 16789.

It is an arithmetic number, because the mean of its divisors is an integer number (1134420).

Almost surely, 2^23431540 is an apocalyptic number.

23431540 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 23431540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27226080).

23431540 is an abundant number, since it is smaller than the sum of its proper divisors (31020620).

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

23431540 is a wasteful number, since it uses less digits than its factorization.

23431540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1552 (or 1550 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 22.

The square root of 23431540 is about 4840.6135974688. The cubic root of 23431540 is about 286.1543008151.

23431540 divided by its sum of digits (22) gives a triangular number (1065070 = T₁₄₅₉).

Adding to 23431540 its reverse (4513432), we get a palindrome (27944972).

It can be divided in two parts, 2343 and 1540, that added together give a palindrome (3883).

The spelling of 23431540 in words is "twenty-three million, four hundred thirty-one thousand, five hundred forty".