851634 has 40 divisors (see below), whose sum is σ = 2183808. Its totient is φ = 243000.

The previous prime is 851633. The next prime is 851639. The reversal of 851634 is 436158.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 851598 and 851607.

It is not an unprimeable number, because it can be changed into a prime (851633) by changing a digit.

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 19 ways as a sum of consecutive naturals, for example, 759 + ... + 1509.

2⁸⁵¹⁶³⁴ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 851634, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1091904).

851634 is an abundant number, since it is smaller than the sum of its proper divisors (1332174).

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

851634 is a wasteful number, since it uses less digits than its factorization.

851634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 772 (or 763 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 851634 is about 922.8401811798. The cubic root of 851634 is about 94.7874843275.

It can be divided in two parts, 851 and 634, that added together give a triangular number (1485 = T₅₄).

The spelling of 851634 in words is "eight hundred fifty-one thousand, six hundred thirty-four".