1645243 has 4 divisors (see below), whose sum is σ = 1742040. Its totient is φ = 1548448.

The previous prime is 1645211. The next prime is 1645249. The reversal of 1645243 is 3425461.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1645243 - 2⁵ = 1645211 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1645249) 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, 48373 + ... + 48406.

It is an arithmetic number, because the mean of its divisors is an integer number (435510).

2^1645243 is an apocalyptic number.

1645243 is a deficient number, since it is larger than the sum of its proper divisors (96797).

1645243 is an equidigital number, since it uses as much as digits as its factorization.

1645243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96796.

The product of its digits is 2880, while the sum is 25.

The square root of 1645243 is about 1282.6702616027. The cubic root of 1645243 is about 118.0529064678.

The spelling of 1645243 in words is "one million, six hundred forty-five thousand, two hundred forty-three".