1205138129 has 8 divisors (see below), whose sum is σ = 1298449152. Its totient is φ = 1111914000.

The previous prime is 1205138059. The next prime is 1205138159. The reversal of 1205138129 is 9218315021.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1205138129 - 2⁸ = 1205137873 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1205138095 and 1205138104.

It is not an unprimeable number, because it can be changed into a prime (1205138159) 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 7 ways as a sum of consecutive naturals, for example, 8672 + ... + 49854.

It is an arithmetic number, because the mean of its divisors is an integer number (162306144).

Almost surely, 2^1205138129 is an apocalyptic number.

It is an amenable number.

1205138129 is a deficient number, since it is larger than the sum of its proper divisors (93311023).

1205138129 is a wasteful number, since it uses less digits than its factorization.

1205138129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43447.

The product of its (nonzero) digits is 4320, while the sum is 32.

The square root of 1205138129 is about 34715.0994381407. The cubic root of 1205138129 is about 1064.1730976153.

The spelling of 1205138129 in words is "one billion, two hundred five million, one hundred thirty-eight thousand, one hundred twenty-nine".