1660840 has 16 divisors (see below), whose sum is σ = 3736980. Its totient is φ = 664320.

The previous prime is 1660837. The next prime is 1660843. The reversal of 1660840 is 480661.

It is an interprime number because it is at equal distance from previous prime (1660837) and next prime (1660843).

It can be written as a sum of positive squares in 2 ways, for example, as 1633284 + 27556 = 1278^2 + 166^2 .

It is not an unprimeable number, because it can be changed into a prime (1660843) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 20721 + ... + 20800.

2^1660840 is an apocalyptic number.

1660840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1660840 is an abundant number, since it is smaller than the sum of its proper divisors (2076140).

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

1660840 is a wasteful number, since it uses less digits than its factorization.

1660840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41532 (or 41528 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 1660840 is about 1288.7358146649. The cubic root of 1660840 is about 118.4247832829.

It can be divided in two parts, 1660 and 840, that added together give a square (2500 = 50²).

The spelling of 1660840 in words is "one million, six hundred sixty thousand, eight hundred forty".