857640 has 64 divisors (see below), whose sum is σ = 2943360. Its totient is φ = 195840.

The previous prime is 857629. The next prime is 857653. The reversal of 857640 is 46758.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 857598 and 857607.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 330 + ... + 1350.

It is an arithmetic number, because the mean of its divisors is an integer number (45990).

2⁸⁵⁷⁶⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 857640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1471680).

857640 is an abundant number, since it is smaller than the sum of its proper divisors (2085720).

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

857640 is a wasteful number, since it uses less digits than its factorization.

857640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1042 (or 1038 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 857640 is about 926.0885486820. The cubic root of 857640 is about 95.0097866187.

The spelling of 857640 in words is "eight hundred fifty-seven thousand, six hundred forty".