12409491 has 4 divisors (see below), whose sum is σ = 16545992. Its totient is φ = 8272992.

The previous prime is 12409471. The next prime is 12409519. The reversal of 12409491 is 19490421.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19490421 = 3 ⋅6496807.

It is not a de Polignac number, because 12409491 - 2⁵ = 12409459 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12409421) 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, 2068246 + ... + 2068251.

It is an arithmetic number, because the mean of its divisors is an integer number (4136498).

Almost surely, 2^12409491 is an apocalyptic number.

12409491 is a deficient number, since it is larger than the sum of its proper divisors (4136501).

12409491 is an equidigital number, since it uses as much as digits as its factorization.

12409491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4136500.

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 12409491 is about 3522.7107460023. The cubic root of 12409491 is about 231.5179435235.

It can be divided in two parts, 1240 and 9491, that added together give a triangular number (10731 = T₁₄₆).

The spelling of 12409491 in words is "twelve million, four hundred nine thousand, four hundred ninety-one".