993978 has 32 divisors (see below), whose sum is σ = 2246400. Its totient is φ = 325728.

The previous prime is 993977. The next prime is 993983. The reversal of 993978 is 879399.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (993977) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4150 + ... + 4382.

It is an arithmetic number, because the mean of its divisors is an integer number (70200).

2⁹⁹³⁹⁷⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 993978, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1123200).

993978 is an abundant number, since it is smaller than the sum of its proper divisors (1252422).

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

993978 is a wasteful number, since it uses less digits than its factorization.

993978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323 (or 317 counting only the distinct ones).

The product of its digits is 122472, while the sum is 45.

The square root of 993978 is about 996.9844532389. The cubic root of 993978 is about 99.7988623745.

The spelling of 993978 in words is "nine hundred ninety-three thousand, nine hundred seventy-eight".