1601820 has 72 divisors (see below), whose sum is σ = 5307120. Its totient is φ = 387840.

The previous prime is 1601813. The next prime is 1601843. The reversal of 1601820 is 281061.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 1601793 and 1601802.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1576 + ... + 2384.

It is an arithmetic number, because the mean of its divisors is an integer number (73710).

2^1601820 is an apocalyptic number.

1601820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1601820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2653560).

1601820 is an abundant number, since it is smaller than the sum of its proper divisors (3705300).

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

1601820 is a wasteful number, since it uses less digits than its factorization.

1601820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 835 (or 830 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 1601820 is about 1265.6302777668. The cubic root of 1601820 is about 117.0050403264.

Adding to 1601820 its reverse (281061), we get a palindrome (1882881).

The spelling of 1601820 in words is "one million, six hundred one thousand, eight hundred twenty".