1291342668 has 144 divisors (see below), whose sum is σ = 3896895744. Its totient is φ = 328997760.

The previous prime is 1291342649. The next prime is 1291342669. The reversal of 1291342668 is 8662431921.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (1291342669) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 340921 + ... + 344687.

It is an arithmetic number, because the mean of its divisors is an integer number (27061776).

Almost surely, 2^1291342668 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1291342668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1948447872).

1291342668 is an abundant number, since it is smaller than the sum of its proper divisors (2605553076).

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

1291342668 is a wasteful number, since it uses less digits than its factorization.

1291342668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3852 (or 3843 counting only the distinct ones).

The product of its digits is 124416, while the sum is 42.

The square root of 1291342668 is about 35935.2566151962. The cubic root of 1291342668 is about 1088.9647798202.

The spelling of 1291342668 in words is "one billion, two hundred ninety-one million, three hundred forty-two thousand, six hundred sixty-eight".