1998630 has 48 divisors (see below), whose sum is σ = 5307120. Its totient is φ = 521664.

The previous prime is 1998617. The next prime is 1998637. The reversal of 1998630 is 368991.

1998630 is a `hidden beast` number, since 19 + 9 + 8 + 630 = 666.

It is a plaindrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1998637) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4561 + ... + 4979.

It is an arithmetic number, because the mean of its divisors is an integer number (110565).

2^1998630 is an apocalyptic number.

1998630 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1998630, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2653560).

1998630 is an abundant number, since it is smaller than the sum of its proper divisors (3308490).

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

1998630 is a wasteful number, since it uses less digits than its factorization.

1998630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 485 (or 482 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 1998630 is about 1413.7291112515. The cubic root of 1998630 is about 125.9633302209.

It can be divided in two parts, 1998 and 630, that added together give a triangular number (2628 = T₇₂).

The spelling of 1998630 in words is "one million, nine hundred ninety-eight thousand, six hundred thirty".