851645 has 8 divisors (see below), whose sum is σ = 1036800. Its totient is φ = 671440.

The previous prime is 851639. The next prime is 851647. The reversal of 851645 is 546158.

It is a happy number.

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

It is not a de Polignac number, because 851645 - 2¹² = 847549 is a prime.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 851645.

It is not an unprimeable number, because it can be changed into a prime (851647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 845 + ... + 1554.

It is an arithmetic number, because the mean of its divisors is an integer number (129600).

2⁸⁵¹⁶⁴⁵ is an apocalyptic number.

It is an amenable number.

851645 is a deficient number, since it is larger than the sum of its proper divisors (185155).

851645 is a wasteful number, since it uses less digits than its factorization.

851645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2475.

The product of its digits is 4800, while the sum is 29.

The square root of 851645 is about 922.8461410224. The cubic root of 851645 is about 94.7878924285.

The spelling of 851645 in words is "eight hundred fifty-one thousand, six hundred forty-five".