851380 has 12 divisors (see below), whose sum is σ = 1787940. Its totient is φ = 340544.

The previous prime is 851363. The next prime is 851381. The reversal of 851380 is 83158.

851380 = T₁₈₆ + T₁₈₇ + ... + T₂₂₅.

It can be written as a sum of positive squares in 2 ways, for example, as 338724 + 512656 = 582^2 + 716^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (851381) by changing a digit.

851380 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21265 + ... + 21304.

It is an arithmetic number, because the mean of its divisors is an integer number (148995).

2⁸⁵¹³⁸⁰ is an apocalyptic number.

It is an amenable number.

851380 is an abundant number, since it is smaller than the sum of its proper divisors (936560).

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

851380 is a wasteful number, since it uses less digits than its factorization.

851380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42578 (or 42576 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 851380 is about 922.7025522887. The cubic root of 851380 is about 94.7780599289.

The spelling of 851380 in words is "eight hundred fifty-one thousand, three hundred eighty".