29661 has 4 divisors (see below), whose sum is σ = 39552. Its totient is φ = 19772.

The previous prime is 29641. The next prime is 29663. The reversal of 29661 is 16692.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 29661 - 2⁵ = 29629 is a prime.

It is a D-number.

29661 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (29663) 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, 4941 + ... + 4946.

It is an arithmetic number, because the mean of its divisors is an integer number (9888).

2²⁹⁶⁶¹ is an apocalyptic number.

It is an amenable number.

29661 is a deficient number, since it is larger than the sum of its proper divisors (9891).

29661 is an equidigital number, since it uses as much as digits as its factorization.

29661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9890.

The product of its digits is 648, while the sum is 24.

The square root of 29661 is about 172.2236917500. The cubic root of 29661 is about 30.9548423327.

The spelling of 29661 in words is "twenty-nine thousand, six hundred sixty-one".