1660890 has 64 divisors (see below), whose sum is σ = 4976640. Its totient is φ = 344640.

The previous prime is 1660889. The next prime is 1660921. The reversal of 1660890 is 980661.

Added to its reverse (980661) it gives a triangular number (2641551 = T₂₂₉₈).

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

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1951 + ... + 2669.

It is an arithmetic number, because the mean of its divisors is an integer number (77760).

2^1660890 is an apocalyptic number.

1660890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1660890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2488320).

1660890 is an abundant number, since it is smaller than the sum of its proper divisors (3315750).

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

1660890 is a wasteful number, since it uses less digits than its factorization.

1660890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 747.

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 1660890 is about 1288.7552133745. The cubic root of 1660890 is about 118.4259716735.

Adding to 1660890 its reverse (980661), we get a triangular number (2641551 = T₂₂₉₈).

It can be divided in two parts, 16 and 60890, that added together give a palindrome (60906).

The spelling of 1660890 in words is "one million, six hundred sixty thousand, eight hundred ninety".