1640845 has 8 divisors (see below), whose sum is σ = 1988064. Its totient is φ = 1299984.

The previous prime is 1640833. The next prime is 1640851. The reversal of 1640845 is 5480461.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1640845 - 2⁹ = 1640333 is a prime.

It is a Duffinian number.

1640845 is a lucky number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 999 + ... + 2068.

It is an arithmetic number, because the mean of its divisors is an integer number (248508).

2^1640845 is an apocalyptic number.

It is an amenable number.

1640845 is a deficient number, since it is larger than the sum of its proper divisors (347219).

1640845 is a wasteful number, since it uses less digits than its factorization.

1640845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3179.

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 1640845 is about 1280.9547220726. The cubic root of 1640845 is about 117.9476211081.

It can be divided in two parts, 1640 and 845, that added together give a triangular number (2485 = T₇₀).

The spelling of 1640845 in words is "one million, six hundred forty thousand, eight hundred forty-five".