1618820 has 48 divisors (see below), whose sum is σ = 4021248. Its totient is φ = 535680.

The previous prime is 1618817. The next prime is 1618823. The reversal of 1618820 is 288161.

It is an interprime number because it is at equal distance from previous prime (1618817) and next prime (1618823).

It is a self number, because there is not a number n which added to its sum of digits gives 1618820.

It is not an unprimeable number, because it can be changed into a prime (1618823) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4154 + ... + 4526.

It is an arithmetic number, because the mean of its divisors is an integer number (83776).

2^1618820 is an apocalyptic number.

1618820 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 1618820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2010624).

1618820 is an abundant number, since it is smaller than the sum of its proper divisors (2402428).

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

1618820 is a wasteful number, since it uses less digits than its factorization.

1618820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 420 (or 418 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 26.

The square root of 1618820 is about 1272.3285739148. The cubic root of 1618820 is about 117.4175066061.

The spelling of 1618820 in words is "one million, six hundred eighteen thousand, eight hundred twenty".