12005136421 has 8 divisors (see below), whose sum is σ = 12217446360. Its totient is φ = 11794633728.

The previous prime is 12005136413. The next prime is 12005136427. The reversal of 12005136421 is 12463150021.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3148444321 + 8856692100 = 56111^2 + 94110^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 12005136421 - 2³ = 12005136413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12005136427) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 438406 + ... + 464983.

It is an arithmetic number, because the mean of its divisors is an integer number (1527180795).

Almost surely, 2^12005136421 is an apocalyptic number.

It is an amenable number.

12005136421 is a deficient number, since it is larger than the sum of its proper divisors (212309939).

12005136421 is an equidigital number, since it uses as much as digits as its factorization.

12005136421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 903623.

The product of its (nonzero) digits is 1440, while the sum is 25.

Adding to 12005136421 its reverse (12463150021), we get a palindrome (24468286442).

The spelling of 12005136421 in words is "twelve billion, five million, one hundred thirty-six thousand, four hundred twenty-one".