840564 has 48 divisors (see below), whose sum is σ = 2242240. Its totient is φ = 272160.

The previous prime is 840557. The next prime is 840571. The reversal of 840564 is 465048.

It is an interprime number because it is at equal distance from previous prime (840557) and next prime (840571).

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

It is a plaindrome in base 13.

It is a congruent number.

It is an unprimeable number.

840564 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 (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4554 + ... + 4734.

2⁸⁴⁰⁵⁶⁴ 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 840564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1121120).

840564 is an abundant number, since it is smaller than the sum of its proper divisors (1401676).

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

840564 is a wasteful number, since it uses less digits than its factorization.

840564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 237 (or 229 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 840564 is about 916.8227745862. The cubic root of 840564 is about 94.3749921787.

The spelling of 840564 in words is "eight hundred forty thousand, five hundred sixty-four".