1645725 has 12 divisors (see below), whose sum is σ = 2721056. Its totient is φ = 877680.

The previous prime is 1645691. The next prime is 1645727. The reversal of 1645725 is 5275461.

It is not a de Polignac number, because 1645725 - 2⁶ = 1645661 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1645692 and 1645701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645727) 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 11 ways as a sum of consecutive naturals, for example, 10897 + ... + 11046.

2^1645725 is an apocalyptic number.

1645725 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1645725 is a deficient number, since it is larger than the sum of its proper divisors (1075331).

1645725 is a wasteful number, since it uses less digits than its factorization.

1645725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21956 (or 21951 counting only the distinct ones).

The product of its digits is 8400, while the sum is 30.

The square root of 1645725 is about 1282.8581371297. The cubic root of 1645725 is about 118.0644338319.

The spelling of 1645725 in words is "one million, six hundred forty-five thousand, seven hundred twenty-five".