1645000 has 80 divisors (see below), whose sum is σ = 4498560. Its totient is φ = 552000.

The previous prime is 1644997. The next prime is 1645003. The reversal of 1645000 is 5461.

It is an interprime number because it is at equal distance from previous prime (1644997) and next prime (1645003).

It is a super-3 number, since 3×1645000³ = 13354233375000000000, which contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645003) 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, 34977 + ... + 35023.

It is an arithmetic number, because the mean of its divisors is an integer number (56232).

2^1645000 is an apocalyptic number.

1645000 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 1645000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2249280).

1645000 is an abundant number, since it is smaller than the sum of its proper divisors (2853560).

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

1645000 is an equidigital number, since it uses as much as digits as its factorization.

1645000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80 (or 61 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 1645000 is about 1282.5755338381. The cubic root of 1645000 is about 118.0470941007.

The spelling of 1645000 in words is "one million, six hundred forty-five thousand".