809749 has 2 divisors, whose sum is σ = 809750. Its totient is φ = 809748.

The previous prime is 809747. The next prime is 809759. The reversal of 809749 is 947908.

It is a happy number.

809749 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 669124 + 140625 = 818^2 + 375^2 .

It is a cyclic number.

It is not a de Polignac number, because 809749 - 2¹ = 809747 is a prime.

Together with 809747, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (809741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 404874 + 404875.

It is an arithmetic number, because the mean of its divisors is an integer number (404875).

2⁸⁰⁹⁷⁴⁹ is an apocalyptic number.

It is an amenable number.

809749 is a deficient number, since it is larger than the sum of its proper divisors (1).

809749 is an equidigital number, since it uses as much as digits as its factorization.

809749 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18144, while the sum is 37.

The square root of 809749 is about 899.8605447512. The cubic root of 809749 is about 93.2073455992.

The spelling of 809749 in words is "eight hundred nine thousand, seven hundred forty-nine".