1664663 has 16 divisors (see below), whose sum is σ = 2236416. Its totient is φ = 1196640.

The previous prime is 1664653. The next prime is 1664681. The reversal of 1664663 is 3664661.

It is a cyclic number.

It is not a de Polignac number, because 1664663 - 2⁸ = 1664407 is a prime.

It is a super-2 number, since 2×1664663² = 5542205807138, which contains 22 as substring.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664633) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 170 + ... + 1832.

It is an arithmetic number, because the mean of its divisors is an integer number (139776).

2^1664663 is an apocalyptic number.

1664663 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

1664663 is a deficient number, since it is larger than the sum of its proper divisors (571753).

1664663 is a wasteful number, since it uses less digits than its factorization.

1664663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1694.

The product of its digits is 15552, while the sum is 32.

The square root of 1664663 is about 1290.2181986005. The cubic root of 1664663 is about 118.5155789069.

The spelling of 1664663 in words is "one million, six hundred sixty-four thousand, six hundred sixty-three".