1788020 has 54 divisors (see below), whose sum is σ = 4250358. Its totient is φ = 631488.

The previous prime is 1788013. The next prime is 1788023. The reversal of 1788020 is 208871.

It can be written as a sum of positive squares in 3 ways, for example, as 8464 + 1779556 = 92^2 + 1334^2 .

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1788023) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 77729 + ... + 77751.

2^1788020 is an apocalyptic number.

1788020 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 1788020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2125179).

1788020 is an abundant number, since it is smaller than the sum of its proper divisors (2462338).

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

1788020 is a wasteful number, since it uses less digits than its factorization.

1788020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81 (or 43 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 26.

The square root of 1788020 is about 1337.1686505449. The cubic root of 1788020 is about 121.3735694220.

The spelling of 1788020 in words is "one million, seven hundred eighty-eight thousand, twenty".