1291142808 has 128 divisors (see below), whose sum is σ = 3793305600. Its totient is φ = 406252800.

The previous prime is 1291142791. The next prime is 1291142851. The reversal of 1291142808 is 8082411921.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 272185 + ... + 276887.

It is an arithmetic number, because the mean of its divisors is an integer number (29635200).

Almost surely, 2^1291142808 is an apocalyptic number.

1291142808 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1291142808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1896652800).

1291142808 is an abundant number, since it is smaller than the sum of its proper divisors (2502162792).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1291142808 is a wasteful number, since it uses less digits than its factorization.

1291142808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4790 (or 4780 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

The square root of 1291142808 is about 35932.4756731289. The cubic root of 1291142808 is about 1088.9085975392.

The spelling of 1291142808 in words is "one billion, two hundred ninety-one million, one hundred forty-two thousand, eight hundred eight".