28891911643108 has 12 divisors (see below), whose sum is σ = 50560915967100. Its totient is φ = 14445935652512.

The previous prime is 28891911643093. The next prime is 28891911643159. The reversal of 28891911643108 is 80134611919882.

It can be written as a sum of positive squares in 2 ways, for example, as 3956749548964 + 24935162094144 = 1989158^2 + 4993512^2 .

It is a super-2 number, since 2×28891911643108² (a number of 28 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1550491 + ... + 7758082.

It is an arithmetic number, because the mean of its divisors is an integer number (4213409663925).

Almost surely, 2^{28891911643108} is an apocalyptic number.

It is an amenable number.

28891911643108 is a deficient number, since it is larger than the sum of its proper divisors (21669004323992).

28891911643108 is a wasteful number, since it uses less digits than its factorization.

28891911643108 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10084526 (or 10084524 counting only the distinct ones).

The product of its (nonzero) digits is 5971968, while the sum is 61.

The spelling of 28891911643108 in words is "twenty-eight trillion, eight hundred ninety-one billion, nine hundred eleven million, six hundred forty-three thousand, one hundred eight".