12091639 has 4 divisors (see below), whose sum is σ = 13819024. Its totient is φ = 10364256.

The previous prime is 12091633. The next prime is 12091649. The reversal of 12091639 is 93619021.

12091639 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: 93619021 = 101 ⋅926921.

It is not a de Polignac number, because 12091639 - 2¹¹ = 12089591 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12091639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12091633) 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, 863682 + ... + 863695.

It is an arithmetic number, because the mean of its divisors is an integer number (3454756).

Almost surely, 2^12091639 is an apocalyptic number.

12091639 is a deficient number, since it is larger than the sum of its proper divisors (1727385).

12091639 is an equidigital number, since it uses as much as digits as its factorization.

12091639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1727384.

The product of its (nonzero) digits is 2916, while the sum is 31.

The square root of 12091639 is about 3477.3034092526. The cubic root of 12091639 is about 229.5241516693.

The spelling of 12091639 in words is "twelve million, ninety-one thousand, six hundred thirty-nine".