23205021 has 16 divisors (see below), whose sum is σ = 35846784. Its totient is φ = 13077504.

The previous prime is 23205011. The next prime is 23205067. The reversal of 23205021 is 12050232.

It is not a de Polignac number, because 23205021 - 2¹³ = 23196829 is a prime.

It is a super-2 number, since 2×23205021² = 1076945999220882, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23205011) 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 15 ways as a sum of consecutive naturals, for example, 6036 + ... + 9101.

It is an arithmetic number, because the mean of its divisors is an integer number (2240424).

Almost surely, 2^23205021 is an apocalyptic number.

23205021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

23205021 is a deficient number, since it is larger than the sum of its proper divisors (12641763).

23205021 is a wasteful number, since it uses less digits than its factorization.

23205021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15220.

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

The square root of 23205021 is about 4817.1590175123. The cubic root of 23205021 is about 285.2292031244.

Adding to 23205021 its reverse (12050232), we get a palindrome (35255253).

It can be divided in two parts, 2 and 3205021, that added together give a palindrome (3205023).

The spelling of 23205021 in words is "twenty-three million, two hundred five thousand, twenty-one".