329661 has 6 divisors (see below), whose sum is σ = 476190. Its totient is φ = 219768.

The previous prime is 329657. The next prime is 329663. The reversal of 329661 is 166923.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 324900 + 4761 = 570^2 + 69^2 .

It is not a de Polignac number, because 329661 - 2² = 329657 is a prime.

It is an Ulam number.

329661 is a lucky number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 329661.

It is not an unprimeable number, because it can be changed into a prime (329663) 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 5 ways as a sum of consecutive naturals, for example, 18306 + ... + 18323.

It is an arithmetic number, because the mean of its divisors is an integer number (79365).

2³²⁹⁶⁶¹ is an apocalyptic number.

It is an amenable number.

329661 is a deficient number, since it is larger than the sum of its proper divisors (146529).

329661 is a wasteful number, since it uses less digits than its factorization.

329661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36635 (or 36632 counting only the distinct ones).

The product of its digits is 1944, while the sum is 27.

The square root of 329661 is about 574.1611272108. The cubic root of 329661 is about 69.0805612283.

It can be divided in two parts, 329 and 661, that added together give a triangular number (990 = T₄₄).

The spelling of 329661 in words is "three hundred twenty-nine thousand, six hundred sixty-one".