9999991264 has 12 divisors (see below), whose sum is σ = 19687482864. Its totient is φ = 4999995616.

The previous prime is 9999991247. The next prime is 9999991279. The reversal of 9999991264 is 4621999999.

It is a self number, because there is not a number n which added to its sum of digits gives 9999991264.

It is a congruent number.

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 as a sum of consecutive naturals, namely, 156249832 + ... + 156249895.

It is an arithmetic number, because the mean of its divisors is an integer number (1640623572).

Almost surely, 2^9999991264 is an apocalyptic number.

It is an amenable number.

9999991264 is a deficient number, since it is larger than the sum of its proper divisors (9687491600).

9999991264 is a wasteful number, since it uses less digits than its factorization.

9999991264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312499737 (or 312499729 counting only the distinct ones).

The product of its digits is 25509168, while the sum is 67.

The square root of 9999991264 is about 99999.9563199905. The cubic root of 9999991264 is about 2154.4340626603.

The spelling of 9999991264 in words is "nine billion, nine hundred ninety-nine million, nine hundred ninety-one thousand, two hundred sixty-four".