23115540 has 96 divisors (see below), whose sum is σ = 75608064. Its totient is φ = 5166720.

The previous prime is 23115539. The next prime is 23115559. The reversal of 23115540 is 4551132.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 19155 + ... + 20325.

It is an arithmetic number, because the mean of its divisors is an integer number (787584).

Almost surely, 2^23115540 is an apocalyptic number.

23115540 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 23115540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37804032).

23115540 is an abundant number, since it is smaller than the sum of its proper divisors (52492524).

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

23115540 is a wasteful number, since it uses less digits than its factorization.

23115540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1237 (or 1235 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 23115540 is about 4807.8623108404. The cubic root of 23115540 is about 284.8621062689.

Adding to 23115540 its reverse (4551132), we get a palindrome (27666672).

The spelling of 23115540 in words is "twenty-three million, one hundred fifteen thousand, five hundred forty".