1664291 has 2 divisors, whose sum is σ = 1664292. Its totient is φ = 1664290.

The previous prime is 1664287. The next prime is 1664353. The reversal of 1664291 is 1924661.

It is a weak prime.

It is an emirp because it is prime and its reverse (1924661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1664291 - 2² = 1664287 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1664251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832145 + 832146.

It is an arithmetic number, because the mean of its divisors is an integer number (832146).

2^1664291 is an apocalyptic number.

1664291 is a deficient number, since it is larger than the sum of its proper divisors (1).

1664291 is an equidigital number, since it uses as much as digits as its factorization.

1664291 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2592, while the sum is 29.

The square root of 1664291 is about 1290.0740288836. The cubic root of 1664291 is about 118.5067500769.

The spelling of 1664291 in words is "one million, six hundred sixty-four thousand, two hundred ninety-one".