1668540 has 24 divisors (see below), whose sum is σ = 4672080. Its totient is φ = 444928.

The previous prime is 1668539. The next prime is 1668551. The reversal of 1668540 is 458661.

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

It is a junction number, because it is equal to n+sod(n) for n = 1668498 and 1668507.

It is a congruent 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 7 ways as a sum of consecutive naturals, for example, 13845 + ... + 13964.

It is an arithmetic number, because the mean of its divisors is an integer number (194670).

2^1668540 is an apocalyptic number.

1668540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1668540 is an abundant number, since it is smaller than the sum of its proper divisors (3003540).

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

1668540 is a wasteful number, since it uses less digits than its factorization.

1668540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27821 (or 27819 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 1668540 is about 1291.7197838541. The cubic root of 1668540 is about 118.6075151620.

The spelling of 1668540 in words is "one million, six hundred sixty-eight thousand, five hundred forty".