998001 has 21 divisors (see below), whose sum is σ = 1537851.
Its totient is φ = 647352.
The previous prime is 997991. The next prime is 998009. The reversal of 998001 is 100899.
The square root of 998001 is 999.
It is a perfect power (a square), and thus also a powerful number.
It can be written as a sum of positive squares in only one way, i.e., 893025 + 104976 = 945^2 + 324^2
It is not a de Polignac number, because 998001 - 215 = 965233 is a prime.
It is a Harshad number since it is a multiple of its sum of digits (27).
It is not an unprimeable number, because it can be changed into a prime (998009) by changing a digit.
It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 26955 + ... + 26991.
It is an arithmetic number, because the mean of its divisors is an integer number (73231).
2998001 is an apocalyptic number.
998001 is the 999-th square number.
998001 is the 500-th centered octagonal number.
It is an amenable number.
998001 is a deficient number, since it is larger than the sum of its proper divisors (539850).
998001 is an frugal number, since it uses more digits than its factorization.
998001 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 92 (or 40 counting only the distinct ones).
The product of its (nonzero) digits is 648, while the sum is 27.
The cubic root of 998001 is about 99.9333222173.
998001 divided by its sum of digits (27) gives a palindrome (36963).
It can be divided in two parts, 99 and 8001, that added together give a square (8100 = 902).
The spelling of 998001 in words is "nine hundred ninety-eight thousand, one".