1664263 has 4 divisors (see below), whose sum is σ = 1691608. Its totient is φ = 1636920.

The previous prime is 1664261. The next prime is 1664279. The reversal of 1664263 is 3624661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3624661 = 1259 ⋅2879.

It is a cyclic number.

It is not a de Polignac number, because 1664263 - 2¹ = 1664261 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664261) 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, 13581 + ... + 13702.

It is an arithmetic number, because the mean of its divisors is an integer number (422902).

2^1664263 is an apocalyptic number.

1664263 is a deficient number, since it is larger than the sum of its proper divisors (27345).

1664263 is an equidigital number, since it uses as much as digits as its factorization.

1664263 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27344.

The product of its digits is 5184, while the sum is 28.

The square root of 1664263 is about 1290.0631767476. The cubic root of 1664263 is about 118.5060854881.

The spelling of 1664263 in words is "one million, six hundred sixty-four thousand, two hundred sixty-three".