878937021921 has 64 divisors (see below), whose sum is σ = 1491273953280. Its totient is φ = 448892928000.

The previous prime is 878937021917. The next prime is 878937022003. The reversal of 878937021921 is 129120739878.

It is not a de Polignac number, because 878937021921 - 2² = 878937021917 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is not an unprimeable number, because it can be changed into a prime (878937021821) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 13921 + ... + 1325921.

It is an arithmetic number, because the mean of its divisors is an integer number (23301155520).

Almost surely, 2^878937021921 is an apocalyptic number.

It is an amenable number.

878937021921 is a deficient number, since it is larger than the sum of its proper divisors (612336931359).

878937021921 is a wasteful number, since it uses less digits than its factorization.

878937021921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1312126.

The product of its (nonzero) digits is 3048192, while the sum is 57.

The spelling of 878937021921 in words is "eight hundred seventy-eight billion, nine hundred thirty-seven million, twenty-one thousand, nine hundred twenty-one".