878126991 has 64 divisors (see below), whose sum is σ = 1420492800. Its totient is φ = 481995360.

The previous prime is 878126983. The next prime is 878127007. The reversal of 878126991 is 199621878.

It is not a de Polignac number, because 878126991 - 2³ = 878126983 is a prime.

It is a super-2 number, since 2×878126991² = 1542214024645428162, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (878126911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3240186 + ... + 3240456.

It is an arithmetic number, because the mean of its divisors is an integer number (22195200).

Almost surely, 2^878126991 is an apocalyptic number.

878126991 is a deficient number, since it is larger than the sum of its proper divisors (542365809).

878126991 is a wasteful number, since it uses less digits than its factorization.

878126991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 409 (or 395 counting only the distinct ones).

The product of its digits is 435456, while the sum is 51.

The square root of 878126991 is about 29633.2075719116. The cubic root of 878126991 is about 957.6036117815.

The spelling of 878126991 in words is "eight hundred seventy-eight million, one hundred twenty-six thousand, nine hundred ninety-one".