1663771 has 2 divisors, whose sum is σ = 1663772. Its totient is φ = 1663770.

The previous prime is 1663763. The next prime is 1663777. The reversal of 1663771 is 1773661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1663771 - 2³ = 1663763 is a prime.

1663771 is a lucky number.

It is equal to p₁₂₅₅₉₉ and since 1663771 and 125599 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (1663777) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 831885 + 831886.

It is an arithmetic number, because the mean of its divisors is an integer number (831886).

2^1663771 is an apocalyptic number.

1663771 is a deficient number, since it is larger than the sum of its proper divisors (1).

1663771 is an equidigital number, since it uses as much as digits as its factorization.

1663771 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5292, while the sum is 31.

The square root of 1663771 is about 1289.8724743167. The cubic root of 1663771 is about 118.4944064965.

The spelling of 1663771 in words is "one million, six hundred sixty-three thousand, seven hundred seventy-one".