1664459 has 2 divisors, whose sum is σ = 1664460. Its totient is φ = 1664458.

The previous prime is 1664447. The next prime is 1664461. The reversal of 1664459 is 9544661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1664459 - 2¹⁶ = 1598923 is a prime.

Together with 1664461, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1664959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832229 + 832230.

It is an arithmetic number, because the mean of its divisors is an integer number (832230).

2^1664459 is an apocalyptic number.

1664459 is a deficient number, since it is larger than the sum of its proper divisors (1).

1664459 is an equidigital number, since it uses as much as digits as its factorization.

1664459 is an evil number, because the sum of its binary digits is even.

The product of its digits is 25920, while the sum is 35.

The square root of 1664459 is about 1290.1391397830. The cubic root of 1664459 is about 118.5107374533.

The spelling of 1664459 in words is "one million, six hundred sixty-four thousand, four hundred fifty-nine".