878921217 has 12 divisors (see below), whose sum is σ = 1270304724. Its totient is φ = 585600480.

The previous prime is 878921159. The next prime is 878921221. The reversal of 878921217 is 712129878.

It can be written as a sum of positive squares in 2 ways, for example, as 58614336 + 820306881 = 7656^2 + 28641^2 .

It is not a de Polignac number, because 878921217 - 2¹⁹ = 878396929 is a prime.

It is a super-2 number, since 2×878921217² = 1545005011385522178, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (878921237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12378 + ... + 43715.

It is an arithmetic number, because the mean of its divisors is an integer number (105858727).

Almost surely, 2^878921217 is an apocalyptic number.

It is an amenable number.

878921217 is a deficient number, since it is larger than the sum of its proper divisors (391383507).

878921217 is a wasteful number, since it uses less digits than its factorization.

878921217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57840 (or 57837 counting only the distinct ones).

The product of its digits is 112896, while the sum is 45.

The square root of 878921217 is about 29646.6054886559. The cubic root of 878921217 is about 957.8922277841.

The spelling of 878921217 in words is "eight hundred seventy-eight million, nine hundred twenty-one thousand, two hundred seventeen".