129649 has 4 divisors (see below), whose sum is σ = 139636. Its totient is φ = 119664.

The previous prime is 129643. The next prime is 129671. The reversal of 129649 is 946921.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 946921 = 151 ⋅6271.

It can be written as a sum of positive squares in 2 ways, for example, as 17424 + 112225 = 132^2 + 335^2 .

It is a cyclic number.

It is not a de Polignac number, because 129649 - 2³ = 129641 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 129649.

It is not an unprimeable number, because it can be changed into a prime (129641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4974 + ... + 4999.

It is an arithmetic number, because the mean of its divisors is an integer number (34909).

2¹²⁹⁶⁴⁹ is an apocalyptic number.

It is an amenable number.

129649 is a deficient number, since it is larger than the sum of its proper divisors (9987).

129649 is an equidigital number, since it uses as much as digits as its factorization.

129649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9986.

The product of its digits is 3888, while the sum is 31.

The square root of 129649 is about 360.0680491241. The cubic root of 129649 is about 50.6123369232.

It can be divided in two parts, 1296 and 49, that multiplied together give a square (63504 = 252²).

The spelling of 129649 in words is "one hundred twenty-nine thousand, six hundred forty-nine".