12005639 has 4 divisors (see below), whose sum is σ = 12027024. Its totient is φ = 11984256.

The previous prime is 12005629. The next prime is 12005641. The reversal of 12005639 is 93650021.

12005639 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93650021 = 73 ⋅1282877.

It is a cyclic number.

It is not a de Polignac number, because 12005639 - 2¹² = 12001543 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 (12005629) 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, 9827 + ... + 10980.

It is an arithmetic number, because the mean of its divisors is an integer number (3006756).

Almost surely, 2^12005639 is an apocalyptic number.

12005639 is a deficient number, since it is larger than the sum of its proper divisors (21385).

12005639 is an equidigital number, since it uses as much as digits as its factorization.

12005639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21384.

The product of its (nonzero) digits is 1620, while the sum is 26.

The square root of 12005639 is about 3464.9154390836. The cubic root of 12005639 is about 228.9787042483.

The spelling of 12005639 in words is "twelve million, five thousand, six hundred thirty-nine".