1689660 has 120 divisors (see below), whose sum is σ = 6098400. Its totient is φ = 383616.

The previous prime is 1689659. The next prime is 1689661. The reversal of 1689660 is 669861.

It is an interprime number because it is at equal distance from previous prime (1689659) and next prime (1689661).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1689661) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 11266 + ... + 11414.

It is an arithmetic number, because the mean of its divisors is an integer number (50820).

2^1689660 is an apocalyptic number.

1689660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1689660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3049200).

1689660 is an abundant number, since it is smaller than the sum of its proper divisors (4408740).

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

1689660 is a wasteful number, since it uses less digits than its factorization.

1689660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177 (or 166 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 1689660 is about 1299.8692241914. The cubic root of 1689660 is about 119.1058540734.

It can be divided in two parts, 16 and 89660, that added together give a triangular number (89676 = T₄₂₃).

The spelling of 1689660 in words is "one million, six hundred eighty-nine thousand, six hundred sixty".