1821630 has 32 divisors (see below), whose sum is σ = 4481568. Its totient is φ = 473600.

The previous prime is 1821613. The next prime is 1821641. The reversal of 1821630 is 361281.

It is a junction number, because it is equal to n+sod(n) for n = 1821597 and 1821606.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 490 + ... + 1970.

It is an arithmetic number, because the mean of its divisors is an integer number (140049).

2^1821630 is an apocalyptic number.

1821630 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 1821630, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2240784).

1821630 is an abundant number, since it is smaller than the sum of its proper divisors (2659938).

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

1821630 is a wasteful number, since it uses less digits than its factorization.

1821630 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1532.

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 1821630 is about 1349.6777393141. The cubic root of 1821630 is about 122.1293530826.

The spelling of 1821630 in words is "one million, eight hundred twenty-one thousand, six hundred thirty".