1291129491 has 12 divisors (see below), whose sum is σ = 1742524808. Its totient is φ = 850368864.

The previous prime is 1291129487. The next prime is 1291129493. The reversal of 1291129491 is 1949211921.

It is not a de Polignac number, because 1291129491 - 2² = 1291129487 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1291129493) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10570 + ... + 51903.

Almost surely, 2^1291129491 is an apocalyptic number.

1291129491 is a deficient number, since it is larger than the sum of its proper divisors (451395317).

1291129491 is an frugal number, since it uses more digits than its factorization.

1291129491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62642 (or 62559 counting only the distinct ones).

The product of its digits is 11664, while the sum is 39.

The square root of 1291129491 is about 35932.2903667439. The cubic root of 1291129491 is about 1088.9048538156.

The spelling of 1291129491 in words is "one billion, two hundred ninety-one million, one hundred twenty-nine thousand, four hundred ninety-one".