978990 has 16 divisors (see below), whose sum is σ = 2349648. Its totient is φ = 261056.

The previous prime is 978973. The next prime is 978997. The reversal of 978990 is 99879.

It is a happy number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (978997) 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 7 ways as a sum of consecutive naturals, for example, 16287 + ... + 16346.

It is an arithmetic number, because the mean of its divisors is an integer number (146853).

2⁹⁷⁸⁹⁹⁰ is an apocalyptic number.

978990 is an abundant number, since it is smaller than the sum of its proper divisors (1370658).

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

978990 is a wasteful number, since it uses less digits than its factorization.

978990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32643.

The product of its (nonzero) digits is 40824, while the sum is 42.

The square root of 978990 is about 989.4392351226. The cubic root of 978990 is about 99.2947039361.

The spelling of 978990 in words is "nine hundred seventy-eight thousand, nine hundred ninety".