851989 has 8 divisors (see below), whose sum is σ = 941760. Its totient is φ = 766656.

The previous prime is 851971. The next prime is 852011. The reversal of 851989 is 989158.

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 851989 - 2⁵ = 851957 is a prime.

It is a super-2 number, since 2×851989² = 1451770512242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (851689) 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, 699 + ... + 1480.

It is an arithmetic number, because the mean of its divisors is an integer number (117720).

2⁸⁵¹⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

851989 is a deficient number, since it is larger than the sum of its proper divisors (89771).

851989 is a wasteful number, since it uses less digits than its factorization.

851989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2219.

The product of its digits is 25920, while the sum is 40.

The square root of 851989 is about 923.0325021363. The cubic root of 851989 is about 94.8006530841.

The spelling of 851989 in words is "eight hundred fifty-one thousand, nine hundred eighty-nine".