1291256329 has 4 divisors (see below), whose sum is σ = 1408643280. Its totient is φ = 1173869380.

The previous prime is 1291256327. The next prime is 1291256341. The reversal of 1291256329 is 9236521921.

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 1291256329 - 2¹ = 1291256327 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1291256291 and 1291256300.

It is not an unprimeable number, because it can be changed into a prime (1291256327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58693459 + ... + 58693480.

It is an arithmetic number, because the mean of its divisors is an integer number (352160820).

Almost surely, 2^1291256329 is an apocalyptic number.

It is an amenable number.

1291256329 is a deficient number, since it is larger than the sum of its proper divisors (117386951).

1291256329 is a wasteful number, since it uses less digits than its factorization.

1291256329 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117386950.

The product of its digits is 58320, while the sum is 40.

The square root of 1291256329 is about 35934.0552818632. The cubic root of 1291256329 is about 1088.9405099322.

The spelling of 1291256329 in words is "one billion, two hundred ninety-one million, two hundred fifty-six thousand, three hundred twenty-nine".