23003521 has 4 divisors (see below), whose sum is σ = 23026500. Its totient is φ = 22980544.

The previous prime is 23003459. The next prime is 23003531. The reversal of 23003521 is 12530032.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 22193521 + 810000 = 4711^2 + 900^2 .

It is a cyclic number.

It is not a de Polignac number, because 23003521 - 2¹⁷ = 22872449 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 23003495 and 23003504.

It is not an unprimeable number, because it can be changed into a prime (23003531) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9916 + ... + 12013.

It is an arithmetic number, because the mean of its divisors is an integer number (5756625).

Almost surely, 2^23003521 is an apocalyptic number.

It is an amenable number.

23003521 is a deficient number, since it is larger than the sum of its proper divisors (22979).

23003521 is a wasteful number, since it uses less digits than its factorization.

23003521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22978.

The product of its (nonzero) digits is 180, while the sum is 16.

The square root of 23003521 is about 4796.1985988906. The cubic root of 23003521 is about 284.4012092094.

Adding to 23003521 its reverse (12530032), we get a palindrome (35533553).

It can be divided in two parts, 2300 and 3521, that multiplied together give a triangular number (8098300 = T₄₀₂₄).

The spelling of 23003521 in words is "twenty-three million, three thousand, five hundred twenty-one".