12021523 has 4 divisors (see below), whose sum is σ = 12065200. Its totient is φ = 11977848.

The previous prime is 12021491. The next prime is 12021539. The reversal of 12021523 is 32512021.

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

It is a cyclic number.

It is not a de Polignac number, because 12021523 - 2⁵ = 12021491 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12021497 and 12021506.

It is not an unprimeable number, because it can be changed into a prime (12021593) 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, 21423 + ... + 21976.

It is an arithmetic number, because the mean of its divisors is an integer number (3016300).

Almost surely, 2^12021523 is an apocalyptic number.

12021523 is a deficient number, since it is larger than the sum of its proper divisors (43677).

12021523 is an equidigital number, since it uses as much as digits as its factorization.

12021523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43676.

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

The square root of 12021523 is about 3467.2068008701. The cubic root of 12021523 is about 229.0796427850.

Adding to 12021523 its reverse (32512021), we get a palindrome (44533544).

It can be divided in two parts, 12021 and 523, that added together give a square (12544 = 112²).

The spelling of 12021523 in words is "twelve million, twenty-one thousand, five hundred twenty-three".