878979021 has 4 divisors (see below), whose sum is σ = 1171972032. Its totient is φ = 585986012.

The previous prime is 878979011. The next prime is 878979061. The reversal of 878979021 is 120979878.

878979021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 878979021 - 2⁶ = 878978957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (878979011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 146496501 + ... + 146496506.

It is an arithmetic number, because the mean of its divisors is an integer number (292993008).

Almost surely, 2^878979021 is an apocalyptic number.

It is an amenable number.

878979021 is a deficient number, since it is larger than the sum of its proper divisors (292993011).

878979021 is a wasteful number, since it uses less digits than its factorization.

878979021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292993010.

The product of its (nonzero) digits is 508032, while the sum is 51.

The square root of 878979021 is about 29647.5803565822. The cubic root of 878979021 is about 957.9132265522.

The spelling of 878979021 in words is "eight hundred seventy-eight million, nine hundred seventy-nine thousand, twenty-one".