1644340 has 12 divisors (see below), whose sum is σ = 3453156. Its totient is φ = 657728.

The previous prime is 1644311. The next prime is 1644341. The reversal of 1644340 is 434461.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 289444 + 1354896 = 538^2 + 1164^2 .

It is a super-3 number, since 3×1644340³ = 13338166034695512000, which contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1644341) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 41089 + ... + 41128.

It is an arithmetic number, because the mean of its divisors is an integer number (287763).

2^1644340 is an apocalyptic number.

1644340 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1644340 is an abundant number, since it is smaller than the sum of its proper divisors (1808816).

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

1644340 is a wasteful number, since it uses less digits than its factorization.

1644340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82226 (or 82224 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 1644340 is about 1282.3182132373. The cubic root of 1644340 is about 118.0313045355.

The spelling of 1644340 in words is "one million, six hundred forty-four thousand, three hundred forty".