1291941809 has 16 divisors (see below), whose sum is σ = 1446999552. Its totient is φ = 1147120128.

The previous prime is 1291941799. The next prime is 1291941829. The reversal of 1291941809 is 9081491921.

It is a cyclic number.

It is not a de Polignac number, because 1291941809 - 2²⁴ = 1275164593 is a prime.

It is a super-2 number, since 2×1291941809² = 3338227275684384962, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1291941809.

It is not an unprimeable number, because it can be changed into a prime (1291941829) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5912 + ... + 51174.

It is an arithmetic number, because the mean of its divisors is an integer number (90437472).

Almost surely, 2^1291941809 is an apocalyptic number.

It is an amenable number.

1291941809 is a deficient number, since it is larger than the sum of its proper divisors (155057743).

1291941809 is a wasteful number, since it uses less digits than its factorization.

1291941809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45376.

The product of its (nonzero) digits is 46656, while the sum is 44.

The square root of 1291941809 is about 35943.5920436453. The cubic root of 1291941809 is about 1089.1331685278.

The spelling of 1291941809 in words is "one billion, two hundred ninety-one million, nine hundred forty-one thousand, eight hundred nine".