840080 has 20 divisors (see below), whose sum is σ = 1953372. Its totient is φ = 336000.

The previous prime is 840067. The next prime is 840083. The reversal of 840080 is 80048.

It can be written as a sum of positive squares in 2 ways, for example, as 274576 + 565504 = 524^2 + 752^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a Smith number, since the sum of its digits (20) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (840083) by changing a digit.

840080 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5171 + ... + 5330.

2⁸⁴⁰⁰⁸⁰ is an apocalyptic number.

840080 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

840080 is an abundant number, since it is smaller than the sum of its proper divisors (1113292).

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

840080 is a wasteful number, since it uses less digits than its factorization.

840080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10514 (or 10508 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 20.

The square root of 840080 is about 916.5587815301. The cubic root of 840080 is about 94.3568748725.

The spelling of 840080 in words is "eight hundred forty thousand, eighty".