129727661 has 16 divisors (see below), whose sum is σ = 155521536. Its totient is φ = 105878016.

The previous prime is 129727651. The next prime is 129727667. The reversal of 129727661 is 166727921.

129727661 is nontrivially palindromic in base 15.

It is not a de Polignac number, because 129727661 - 2¹⁰ = 129726637 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129727667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6845 + ... + 17501.

It is an arithmetic number, because the mean of its divisors is an integer number (9720096).

Almost surely, 2^129727661 is an apocalyptic number.

It is an amenable number.

129727661 is a deficient number, since it is larger than the sum of its proper divisors (25793875).

129727661 is a wasteful number, since it uses less digits than its factorization.

129727661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10748.

The product of its digits is 63504, while the sum is 41.

The square root of 129727661 is about 11389.8051344174. The cubic root of 129727661 is about 506.2257073950.

The spelling of 129727661 in words is "one hundred twenty-nine million, seven hundred twenty-seven thousand, six hundred sixty-one".