1664123 has 2 divisors, whose sum is σ = 1664124. Its totient is φ = 1664122.

The previous prime is 1664101. The next prime is 1664227. The reversal of 1664123 is 3214661.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1664123 - 2⁸ = 1663867 is a prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (1661123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832061 + 832062.

It is an arithmetic number, because the mean of its divisors is an integer number (832062).

2^1664123 is an apocalyptic number.

1664123 is a deficient number, since it is larger than the sum of its proper divisors (1).

1664123 is an equidigital number, since it uses as much as digits as its factorization.

1664123 is an evil number, because the sum of its binary digits is even.

The product of its digits is 864, while the sum is 23.

The square root of 1664123 is about 1290.0089146979. The cubic root of 1664123 is about 118.5027624321.

Subtracting from 1664123 its sum of digits (23), we obtain a square (1664100 = 1290²).

Adding to 1664123 its reverse (3214661), we get a palindrome (4878784).

The spelling of 1664123 in words is "one million, six hundred sixty-four thousand, one hundred twenty-three".