129756241 has 4 divisors (see below), whose sum is σ = 132773872. Its totient is φ = 126738612.

The previous prime is 129756239. The next prime is 129756269. The reversal of 129756241 is 142657921.

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, and also an emirpimes, since its reverse is a distinct semiprime: 142657921 = 7 ⋅20379703.

It is a cyclic number.

It is not a de Polignac number, because 129756241 - 2¹ = 129756239 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 129756241.

It is not an unprimeable number, because it can be changed into a prime (129750241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1508751 + ... + 1508836.

It is an arithmetic number, because the mean of its divisors is an integer number (33193468).

Almost surely, 2^129756241 is an apocalyptic number.

It is an amenable number.

129756241 is a deficient number, since it is larger than the sum of its proper divisors (3017631).

129756241 is an equidigital number, since it uses as much as digits as its factorization.

129756241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3017630.

The product of its digits is 30240, while the sum is 37.

The square root of 129756241 is about 11391.0596960950. The cubic root of 129756241 is about 506.2628798024.

The spelling of 129756241 in words is "one hundred twenty-nine million, seven hundred fifty-six thousand, two hundred forty-one".