1291547868 has 96 divisors (see below), whose sum is σ = 3448295424. Its totient is φ = 372722688.

The previous prime is 1291547843. The next prime is 1291547869. The reversal of 1291547868 is 8687451921.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a self number, because there is not a number n which added to its sum of digits gives 1291547868.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291547869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 972621 + ... + 973947.

It is an arithmetic number, because the mean of its divisors is an integer number (35919744).

Almost surely, 2^1291547868 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 1291547868, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1724147712).

1291547868 is an abundant number, since it is smaller than the sum of its proper divisors (2156747556).

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

1291547868 is a wasteful number, since it uses less digits than its factorization.

1291547868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1731 (or 1729 counting only the distinct ones).

The product of its digits is 967680, while the sum is 51.

The square root of 1291547868 is about 35938.1116365343. Note that the first 3 decimals coincide. The cubic root of 1291547868 is about 1089.0224571879.

The spelling of 1291547868 in words is "one billion, two hundred ninety-one million, five hundred forty-seven thousand, eight hundred sixty-eight".