851997 has 8 divisors (see below), whose sum is σ = 1149120. Its totient is φ = 561440.

The previous prime is 851971. The next prime is 852011. The reversal of 851997 is 799158.

851997 = 209² + 210² + ... + 226².

It is a happy number.

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 851997 - 2¹⁰ = 850973 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (851957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1329 + ... + 1862.

It is an arithmetic number, because the mean of its divisors is an integer number (143640).

2⁸⁵¹⁹⁹⁷ is an apocalyptic number.

It is an amenable number.

851997 is a deficient number, since it is larger than the sum of its proper divisors (297123).

851997 is a wasteful number, since it uses less digits than its factorization.

851997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3283.

The product of its digits is 22680, while the sum is 39.

The square root of 851997 is about 923.0368356680. The cubic root of 851997 is about 94.8009498027.

The spelling of 851997 in words is "eight hundred fifty-one thousand, nine hundred ninety-seven".