23520021 has 8 divisors (see below), whose sum is σ = 35840064. Its totient is φ = 13440000.

The previous prime is 23520017. The next prime is 23520031. The reversal of 23520021 is 12002532.

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

It is not a de Polignac number, because 23520021 - 2² = 23520017 is a prime.

It is a Smith number, since the sum of its digits (15) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23520031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 559980 + ... + 560021.

It is an arithmetic number, because the mean of its divisors is an integer number (4480008).

Almost surely, 2^23520021 is an apocalyptic number.

23520021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

23520021 is a deficient number, since it is larger than the sum of its proper divisors (12320043).

23520021 is a wasteful number, since it uses less digits than its factorization.

23520021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1120011.

The product of its (nonzero) digits is 120, while the sum is 15.

The square root of 23520021 is about 4849.7444262559. The cubic root of 23520021 is about 286.5140355383.

Adding to 23520021 its reverse (12002532), we get a palindrome (35522553).

The spelling of 23520021 in words is "twenty-three million, five hundred twenty thousand, twenty-one".