1663309 has 2 divisors, whose sum is σ = 1663310. Its totient is φ = 1663308.

The previous prime is 1663303. The next prime is 1663327. The reversal of 1663309 is 9033661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1387684 + 275625 = 1178^2 + 525^2 .

It is a cyclic number.

It is not a de Polignac number, because 1663309 - 2³ = 1663301 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1663301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 831654 + 831655.

It is an arithmetic number, because the mean of its divisors is an integer number (831655).

2^1663309 is an apocalyptic number.

It is an amenable number.

1663309 is a deficient number, since it is larger than the sum of its proper divisors (1).

1663309 is an equidigital number, since it uses as much as digits as its factorization.

1663309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2916, while the sum is 28.

The square root of 1663309 is about 1289.6933744111. The cubic root of 1663309 is about 118.4834375423.

Adding to 1663309 its product of nonzero digits (2916), we get a triangular number (1666225 = T₁₈₂₅).

The spelling of 1663309 in words is "one million, six hundred sixty-three thousand, three hundred nine".