987978 has 8 divisors (see below), whose sum is σ = 1975968. Its totient is φ = 329324.

The previous prime is 987971. The next prime is 987979. The reversal of 987978 is 879789.

987978 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

987978 is an admirable number.

It is a super-2 number, since 2×987978² = 1952201056968, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (987971) by changing a digit.

987978 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 3 ways as a sum of consecutive naturals, for example, 82326 + ... + 82337.

It is an arithmetic number, because the mean of its divisors is an integer number (246996).

2⁹⁸⁷⁹⁷⁸ is an apocalyptic number.

987978 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

987978 is a wasteful number, since it uses less digits than its factorization.

987978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164668.

The product of its digits is 254016, while the sum is 48.

The square root of 987978 is about 993.9708245215. The cubic root of 987978 is about 99.5976499825.

The spelling of 987978 in words is "nine hundred eighty-seven thousand, nine hundred seventy-eight".