1664501 has 2 divisors, whose sum is σ = 1664502. Its totient is φ = 1664500.

The previous prime is 1664461. The next prime is 1664543. The reversal of 1664501 is 1054661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1378276 + 286225 = 1174^2 + 535^2 .

It is a cyclic number.

It is not a de Polignac number, because 1664501 - 2⁶ = 1664437 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1664561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832250 + 832251.

It is an arithmetic number, because the mean of its divisors is an integer number (832251).

2^1664501 is an apocalyptic number.

It is an amenable number.

1664501 is a deficient number, since it is larger than the sum of its proper divisors (1).

1664501 is an equidigital number, since it uses as much as digits as its factorization.

1664501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 1664501 is about 1290.1554169944. The cubic root of 1664501 is about 118.5117342555.

The spelling of 1664501 in words is "one million, six hundred sixty-four thousand, five hundred one".