851680 has 24 divisors (see below), whose sum is σ = 2012472. Its totient is φ = 340608.

The previous prime is 851677. The next prime is 851689. The reversal of 851680 is 86158.

It is a happy number.

It is a Smith number, since the sum of its digits (28) coincides with the sum of the digits of its prime factors.

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 3 ways as a sum of consecutive naturals, for example, 2502 + ... + 2821.

It is an arithmetic number, because the mean of its divisors is an integer number (83853).

2⁸⁵¹⁶⁸⁰ is an apocalyptic number.

851680 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

851680 is an abundant number, since it is smaller than the sum of its proper divisors (1160792).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

851680 is a wasteful number, since it uses less digits than its factorization.

851680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5338 (or 5330 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 851680 is about 922.8651039020. The cubic root of 851680 is about 94.7891909080.

The spelling of 851680 in words is "eight hundred fifty-one thousand, six hundred eighty".