23201521 has 4 divisors (see below), whose sum is σ = 26516032. Its totient is φ = 19887012.

The previous prime is 23201513. The next prime is 23201539. The reversal of 23201521 is 12510232.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 23201521 - 2³ = 23201513 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 23201495 and 23201504.

It is not an unprimeable number, because it can be changed into a prime (23201501) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 1657245 + ... + 1657258.

It is an arithmetic number, because the mean of its divisors is an integer number (6629008).

Almost surely, 2^23201521 is an apocalyptic number.

It is an amenable number.

23201521 is a deficient number, since it is larger than the sum of its proper divisors (3314511).

23201521 is an equidigital number, since it uses as much as digits as its factorization.

23201521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3314510.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 23201521 is about 4816.7957191477. The cubic root of 23201521 is about 285.2148620843.

Adding to 23201521 its reverse (12510232), we get a palindrome (35711753).

The spelling of 23201521 in words is "twenty-three million, two hundred one thousand, five hundred twenty-one".