43649 has 2 divisors, whose sum is σ = 43650. Its totient is φ = 43648.

The previous prime is 43633. The next prime is 43651. The reversal of 43649 is 94634.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 37249 + 6400 = 193^2 + 80^2 .

It is a cyclic number.

It is not a de Polignac number, because 43649 - 2⁴ = 43633 is a prime.

It is a Sophie Germain prime.

Together with 43651, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a plaindrome in base 15.

It is a nialpdrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21824 + 21825.

It is an arithmetic number, because the mean of its divisors is an integer number (21825).

2⁴³⁶⁴⁹ is an apocalyptic number.

It is an amenable number.

43649 is a deficient number, since it is larger than the sum of its proper divisors (1).

43649 is an equidigital number, since it uses as much as digits as its factorization.

43649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2592, while the sum is 26.

The square root of 43649 is about 208.9234309502. The cubic root of 43649 is about 35.2093574468.

The spelling of 43649 in words is "forty-three thousand, six hundred forty-nine".