1998730 has 8 divisors (see below), whose sum is σ = 3597732. Its totient is φ = 799488.

The previous prime is 1998727. The next prime is 1998739. The reversal of 1998730 is 378991.

It can be written as a sum of positive squares in 2 ways, for example, as 1819801 + 178929 = 1349^2 + 423^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×1998730² = 7989843225800, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1998730.

It is not an unprimeable number, because it can be changed into a prime (1998739) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 99927 + ... + 99946.

2^1998730 is an apocalyptic number.

1998730 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1998730 is a deficient number, since it is larger than the sum of its proper divisors (1599002).

1998730 is a wasteful number, since it uses less digits than its factorization.

1998730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199880.

The product of its (nonzero) digits is 13608, while the sum is 37.

The square root of 1998730 is about 1413.7644782636. The cubic root of 1998730 is about 125.9654310138.

The spelling of 1998730 in words is "one million, nine hundred ninety-eight thousand, seven hundred thirty".