1645420 has 72 divisors (see below), whose sum is σ = 4251744.
Its totient is φ = 532224.
The previous prime is 1645417. The next prime is 1645421. The reversal of 1645420 is 245461.
It can be divided in two parts, 1645 and 420, that multiplied together give a triangular number (690900 = T1175).
It is a junction number, because it is equal to n+sod(n) for n = 1645391 and 1645400.
It is not an unprimeable number, because it can be changed into a prime (1645421) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (11) of ones.
It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 22504 + ... + 22576.
It is an arithmetic number, because the mean of its divisors is an integer number (59052).
21645420 is an apocalyptic number.
1645420 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 1645420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2125872).
1645420 is an abundant number, since it is smaller than the sum of its proper divisors (2606324).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
1645420 is a wasteful number, since it uses less digits than its factorization.
1645420 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 119 (or 110 counting only the distinct ones).
The product of its (nonzero) digits is 960, while the sum is 22.
The square root of 1645420 is about 1282.7392564352.
The cubic root of 1645420 is about 118.0571398070.
The spelling of 1645420 in words is "one million, six hundred forty-five thousand, four hundred twenty".