1665020 has 36 divisors (see below), whose sum is σ = 4069800. Its totient is φ = 570528.

The previous prime is 1665007. The next prime is 1665023. The reversal of 1665020 is 205661.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 1664983 and 1665001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665023) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 131 + ... + 1829.

It is an arithmetic number, because the mean of its divisors is an integer number (113050).

2^1665020 is an apocalyptic number.

1665020 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 1665020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2034900).

1665020 is an abundant number, since it is smaller than the sum of its proper divisors (2404780).

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

1665020 is a wasteful number, since it uses less digits than its factorization.

1665020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1722 (or 1713 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 1665020 is about 1290.3565398757. The cubic root of 1665020 is about 118.5240504989.

The spelling of 1665020 in words is "one million, six hundred sixty-five thousand, twenty".