1605420 has 60 divisors (see below), whose sum is σ = 5041344. Its totient is φ = 427680.

The previous prime is 1605419. The next prime is 1605421. The reversal of 1605420 is 245061.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1605419) and next prime (1605421).

It is a tau number, because it is divible by the number of its divisors (60).

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 = 1605393 and 1605402.

It is not an unprimeable number, because it can be changed into a prime (1605421) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1125 + ... + 2115.

2^1605420 is an apocalyptic number.

1605420 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 1605420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2520672).

1605420 is an abundant number, since it is smaller than the sum of its proper divisors (3435924).

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

1605420 is a wasteful number, since it uses less digits than its factorization.

1605420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1012 (or 1001 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 1605420 is about 1267.0516958672. The cubic root of 1605420 is about 117.0926288161.

It can be divided in two parts, 1605 and 420, that added together give a square (2025 = 45²).

The spelling of 1605420 in words is "one million, six hundred five thousand, four hundred twenty".