1646664 has 16 divisors (see below), whose sum is σ = 4116720. Its totient is φ = 548880.

The previous prime is 1646647. The next prime is 1646669. The reversal of 1646664 is 4666461.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (1646669) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34282 + ... + 34329.

It is an arithmetic number, because the mean of its divisors is an integer number (257295).

2^1646664 is an apocalyptic number.

It is an amenable number.

1646664 is an abundant number, since it is smaller than the sum of its proper divisors (2470056).

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

1646664 is a wasteful number, since it uses less digits than its factorization.

1646664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68620 (or 68616 counting only the distinct ones).

The product of its digits is 20736, while the sum is 33.

The square root of 1646664 is about 1283.2240646123. The cubic root of 1646664 is about 118.0868842058.

The spelling of 1646664 in words is "one million, six hundred forty-six thousand, six hundred sixty-four".