129664 has 16 divisors (see below), whose sum is σ = 258570. Its totient is φ = 64768.

The previous prime is 129643. The next prime is 129671. The reversal of 129664 is 466921.

It can be written as a sum of positive squares in only one way, i.e., 129600 + 64 = 360^2 + 8^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 379 + ... + 634.

2¹²⁹⁶⁶⁴ is an apocalyptic number.

It is an amenable number.

129664 is a deficient number, since it is larger than the sum of its proper divisors (128906).

129664 is an equidigital number, since it uses as much as digits as its factorization.

129664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1027 (or 1015 counting only the distinct ones).

The product of its digits is 2592, while the sum is 28.

The square root of 129664 is about 360.0888779177. The cubic root of 129664 is about 50.6142887464.

It can be divided in two parts, 1296 and 64, that multiplied together give a square (82944 = 288²).

The spelling of 129664 in words is "one hundred twenty-nine thousand, six hundred sixty-four".