878640 has 80 divisors (see below), whose sum is σ = 3118848. Its totient is φ = 200448.

The previous prime is 878629. The next prime is 878641. The reversal of 878640 is 46878.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (878641) by changing a digit.

878640 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1419 + ... + 1941.

2⁸⁷⁸⁶⁴⁰ is an apocalyptic number.

878640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 878640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1559424).

878640 is an abundant number, since it is smaller than the sum of its proper divisors (2240208).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

878640 is a wasteful number, since it uses less digits than its factorization.

878640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 546 (or 540 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 33.

The square root of 878640 is about 937.3579892442. The cubic root of 878640 is about 95.7790055444.

The spelling of 878640 in words is "eight hundred seventy-eight thousand, six hundred forty".