1684880 has 20 divisors (see below), whose sum is σ = 3917532. Its totient is φ = 673920.

The previous prime is 1684877. The next prime is 1684883. The reversal of 1684880 is 884861.

It is an interprime number because it is at equal distance from previous prime (1684877) and next prime (1684883).

It can be written as a sum of positive squares in 2 ways, for example, as 1290496 + 394384 = 1136^2 + 628^2 .

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

It is a super-2 number, since 2×1684880² = 5677641228800, which contains 22 as substring.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 1684880.

It is not an unprimeable number, because it can be changed into a prime (1684883) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10451 + ... + 10610.

2^1684880 is an apocalyptic number.

1684880 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1684880 is an abundant number, since it is smaller than the sum of its proper divisors (2232652).

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

1684880 is a wasteful number, since it uses less digits than its factorization.

1684880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21074 (or 21068 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 35.

The square root of 1684880 is about 1298.0292754788. The cubic root of 1684880 is about 118.9934323047.

It can be divided in two parts, 168 and 4880, that multiplied together give a triangular number (819840 = T₁₂₈₀).

The spelling of 1684880 in words is "one million, six hundred eighty-four thousand, eight hundred eighty".