12040221521 has 4 divisors (see below), whose sum is σ = 12068821044. Its totient is φ = 12011622000.

The previous prime is 12040221517. The next prime is 12040221547. The reversal of 12040221521 is 12512204021.

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 2584603921 + 9455617600 = 50839^2 + 97240^2 .

It is a cyclic number.

It is not a de Polignac number, because 12040221521 - 2² = 12040221517 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12040221493 and 12040221502.

It is not an unprimeable number, because it can be changed into a prime (12040221121) 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, 14299130 + ... + 14299971.

It is an arithmetic number, because the mean of its divisors is an integer number (3017205261).

Almost surely, 2^12040221521 is an apocalyptic number.

It is an amenable number.

12040221521 is a deficient number, since it is larger than the sum of its proper divisors (28599523).

12040221521 is an equidigital number, since it uses as much as digits as its factorization.

12040221521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28599522.

The product of its (nonzero) digits is 320, while the sum is 20.

Adding to 12040221521 its reverse (12512204021), we get a palindrome (24552425542).

The spelling of 12040221521 in words is "twelve billion, forty million, two hundred twenty-one thousand, five hundred twenty-one".