1664664 has 32 divisors (see below), whose sum is σ = 4200000. Its totient is φ = 549792.

The previous prime is 1664653. The next prime is 1664681. The reversal of 1664664 is 4664661.

It is a super-2 number, since 2×1664664² = 5542212465792, which contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3087 + ... + 3585.

It is an arithmetic number, because the mean of its divisors is an integer number (131250).

2^1664664 is an apocalyptic number.

It is an amenable number.

1664664 is an abundant number, since it is smaller than the sum of its proper divisors (2535336).

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

1664664 is a wasteful number, since it uses less digits than its factorization.

1664664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 647 (or 643 counting only the distinct ones).

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

The square root of 1664664 is about 1290.2185861318. The cubic root of 1664664 is about 118.5156026385.

The spelling of 1664664 in words is "one million, six hundred sixty-four thousand, six hundred sixty-four".