1644145 has 4 divisors (see below), whose sum is σ = 1972980. Its totient is φ = 1315312.

The previous prime is 1644143. The next prime is 1644163. The reversal of 1644145 is 5414461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5414461 = 13 ⋅416497.

It can be written as a sum of positive squares in 2 ways, for example, as 1065024 + 579121 = 1032^2 + 761^2 .

It is a cyclic number.

It is not a de Polignac number, because 1644145 - 2¹ = 1644143 is a prime.

It is a super-3 number, since 3×1644145³ = 13333421333575045875, which contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (1644143) 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, 164410 + ... + 164419.

It is an arithmetic number, because the mean of its divisors is an integer number (493245).

2^1644145 is an apocalyptic number.

It is an amenable number.

1644145 is a deficient number, since it is larger than the sum of its proper divisors (328835).

1644145 is an equidigital number, since it uses as much as digits as its factorization.

1644145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 328834.

The product of its digits is 1920, while the sum is 25.

The square root of 1644145 is about 1282.2421768137. The cubic root of 1644145 is about 118.0266386282.

The spelling of 1644145 in words is "one million, six hundred forty-four thousand, one hundred forty-five".