49809 has 4 divisors (see below), whose sum is σ = 66416. Its totient is φ = 33204.

The previous prime is 49807. The next prime is 49811. The reversal of 49809 is 90894.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (49807) and next prime (49811).

It is not a de Polignac number, because 49809 - 2¹ = 49807 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (49801) 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, 8299 + ... + 8304.

It is an arithmetic number, because the mean of its divisors is an integer number (16604).

2⁴⁹⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

49809 is a deficient number, since it is larger than the sum of its proper divisors (16607).

49809 is a wasteful number, since it uses less digits than its factorization.

49809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16606.

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

The square root of 49809 is about 223.1793001154. The cubic root of 49809 is about 36.7933451262.

It can be divided in two parts, 49 and 809, that added together give a palindrome (858).

The spelling of 49809 in words is "forty-nine thousand, eight hundred nine".