998790 has 48 divisors (see below), whose sum is σ = 2608848. Its totient is φ = 244608.

The previous prime is 998779. The next prime is 998813. The reversal of 998790 is 97899.

998790 = 28² + 29² + ... + 144².

It is a happy number.

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

998790 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 23 ways as a sum of consecutive naturals, for example, 4972 + ... + 5168.

It is an arithmetic number, because the mean of its divisors is an integer number (54351).

2⁹⁹⁸⁷⁹⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 998790, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1304424).

998790 is an abundant number, since it is smaller than the sum of its proper divisors (1610058).

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

998790 is a wasteful number, since it uses less digits than its factorization.

998790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 233 (or 220 counting only the distinct ones).

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

The square root of 998790 is about 999.3948168767. The cubic root of 998790 is about 99.9596503879.

The spelling of 998790 in words is "nine hundred ninety-eight thousand, seven hundred ninety".