1291249729 has 8 divisors (see below), whose sum is σ = 1609869888. Its totient is φ = 1006168560.

The previous prime is 1291249723. The next prime is 1291249763. The reversal of 1291249729 is 9279421921.

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 1291249729 - 2⁹ = 1291249217 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1291249723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8384662 + ... + 8384815.

It is an arithmetic number, because the mean of its divisors is an integer number (201233736).

Almost surely, 2^1291249729 is an apocalyptic number.

It is an amenable number.

1291249729 is a deficient number, since it is larger than the sum of its proper divisors (318620159).

1291249729 is a wasteful number, since it uses less digits than its factorization.

1291249729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16769495.

The product of its digits is 163296, while the sum is 46.

The square root of 1291249729 is about 35933.9634468562. The cubic root of 1291249729 is about 1088.9386546281.

The spelling of 1291249729 in words is "one billion, two hundred ninety-one million, two hundred forty-nine thousand, seven hundred twenty-nine".