1291086864 has 50 divisors (see below), whose sum is σ = 3736783710. Its totient is φ = 430361856.

The previous prime is 1291086799. The next prime is 1291086877. The reversal of 1291086864 is 4686801921.

It can be written as a sum of positive squares in only one way, i.e., 748569600 + 542517264 = 27360^2 + 23292^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 496809 + ... + 499400.

Almost surely, 2^1291086864 is an apocalyptic number.

It is an amenable number.

1291086864 is an abundant number, since it is smaller than the sum of its proper divisors (2445696846).

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

1291086864 is an equidigital number, since it uses as much as digits as its factorization.

1291086864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 996229 (or 996214 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 45.

The square root of 1291086864 is about 35931.6972045574. The cubic root of 1291086864 is about 1088.8928701846.

The spelling of 1291086864 in words is "one billion, two hundred ninety-one million, eighty-six thousand, eight hundred sixty-four".