129241561 has 4 divisors (see below), whose sum is σ = 129315124. Its totient is φ = 129168000.

The previous prime is 129241549. The next prime is 129241589. The reversal of 129241561 is 165142921.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 30735936 + 98505625 = 5544^2 + 9925^2 .

It is a cyclic number.

It is not a de Polignac number, because 129241561 - 2⁵ = 129241529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129241501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34080 + ... + 37681.

It is an arithmetic number, because the mean of its divisors is an integer number (32328781).

Almost surely, 2^129241561 is an apocalyptic number.

It is an amenable number.

129241561 is a deficient number, since it is larger than the sum of its proper divisors (73563).

129241561 is an equidigital number, since it uses as much as digits as its factorization.

129241561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73562.

The product of its digits is 4320, while the sum is 31.

The square root of 129241561 is about 11368.4458480480. The cubic root of 129241561 is about 505.5926264935.

The spelling of 129241561 in words is "one hundred twenty-nine million, two hundred forty-one thousand, five hundred sixty-one".