1663538671 has 2 divisors, whose sum is σ = 1663538672. Its totient is φ = 1663538670.

The previous prime is 1663538627. The next prime is 1663538713. The reversal of 1663538671 is 1768353661.

It is a strong prime.

It is an emirp because it is prime and its reverse (1768353661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1663538671 - 2¹⁹ = 1663014383 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1663538171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 831769335 + 831769336.

It is an arithmetic number, because the mean of its divisors is an integer number (831769336).

Almost surely, 2^1663538671 is an apocalyptic number.

1663538671 is a deficient number, since it is larger than the sum of its proper divisors (1).

1663538671 is an equidigital number, since it uses as much as digits as its factorization.

1663538671 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 544320, while the sum is 46.

The square root of 1663538671 is about 40786.5010879825. The cubic root of 1663538671 is about 1184.8889071972. Note that the first 3 decimals are identical.

The spelling of 1663538671 in words is "one billion, six hundred sixty-three million, five hundred thirty-eight thousand, six hundred seventy-one".