23121543 has 8 divisors (see below), whose sum is σ = 31128448. Its totient is φ = 15264504.

The previous prime is 23121521. The next prime is 23121557. The reversal of 23121543 is 34512132.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 23121543 - 2⁹ = 23121031 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23121583) 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, 37105 + ... + 37722.

It is an arithmetic number, because the mean of its divisors is an integer number (3891056).

Almost surely, 2^23121543 is an apocalyptic number.

23121543 is a deficient number, since it is larger than the sum of its proper divisors (8006905).

23121543 is a wasteful number, since it uses less digits than its factorization.

23121543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74933.

The product of its digits is 720, while the sum is 21.

The square root of 23121543 is about 4808.4865602391. The cubic root of 23121543 is about 284.8867632632.

Adding to 23121543 its reverse (34512132), we get a palindrome (57633675).

The spelling of 23121543 in words is "twenty-three million, one hundred twenty-one thousand, five hundred forty-three".