23543721 has 6 divisors (see below), whose sum is σ = 34007610. Its totient is φ = 15695808.

The previous prime is 23543711. The next prime is 23543749. The reversal of 23543721 is 12734532.

It can be written as a sum of positive squares in only one way, i.e., 23474025 + 69696 = 4845^2 + 264^2 .

It is not a de Polignac number, because 23543721 - 2⁷ = 23543593 is a prime.

It is a super-3 number, since 3×23543721³ (a number of 23 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (23543711) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1307976 + ... + 1307993.

It is an arithmetic number, because the mean of its divisors is an integer number (5667935).

Almost surely, 2^23543721 is an apocalyptic number.

It is an amenable number.

23543721 is a deficient number, since it is larger than the sum of its proper divisors (10463889).

23543721 is a wasteful number, since it uses less digits than its factorization.

23543721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2615975 (or 2615972 counting only the distinct ones).

The product of its digits is 5040, while the sum is 27.

The square root of 23543721 is about 4852.1872387615. The cubic root of 23543721 is about 286.6102387281.

It can be divided in two parts, 235 and 43721, that added together give a triangular number (43956 = T₂₉₆).

The spelling of 23543721 in words is "twenty-three million, five hundred forty-three thousand, seven hundred twenty-one".