12495809 has 4 divisors (see below), whose sum is σ = 12518340. Its totient is φ = 12473280.

The previous prime is 12495797. The next prime is 12495827. The reversal of 12495809 is 90859421.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90859421 = 433 ⋅209837.

It can be written as a sum of positive squares in 2 ways, for example, as 5880625 + 6615184 = 2425^2 + 2572^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12495809 is a prime.

It is a super-2 number, since 2×12495809² = 312290485128962, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (12495829) 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, 10412 + ... + 11549.

It is an arithmetic number, because the mean of its divisors is an integer number (3129585).

Almost surely, 2^12495809 is an apocalyptic number.

It is an amenable number.

12495809 is a deficient number, since it is larger than the sum of its proper divisors (22531).

12495809 is an equidigital number, since it uses as much as digits as its factorization.

12495809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22530.

The product of its (nonzero) digits is 25920, while the sum is 38.

The square root of 12495809 is about 3534.9411593406. The cubic root of 12495809 is about 232.0535015830.

The spelling of 12495809 in words is "twelve million, four hundred ninety-five thousand, eight hundred nine".