1666420 has 24 divisors (see below), whose sum is σ = 3999744. Its totient is φ = 571296.

The previous prime is 1666417. The next prime is 1666421. The reversal of 1666420 is 246661.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5812 + ... + 6091.

It is an arithmetic number, because the mean of its divisors is an integer number (166656).

2^1666420 is an apocalyptic number.

1666420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1666420 is an abundant number, since it is smaller than the sum of its proper divisors (2333324).

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

1666420 is a wasteful number, since it uses less digits than its factorization.

1666420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11919 (or 11917 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 1666420 is about 1290.8989116116. The cubic root of 1666420 is about 118.5572607477.

The spelling of 1666420 in words is "one million, six hundred sixty-six thousand, four hundred twenty".