1663459381 has 2 divisors, whose sum is σ = 1663459382. Its totient is φ = 1663459380.

The previous prime is 1663459379. The next prime is 1663459387. The reversal of 1663459381 is 1839543661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1597281156 + 66178225 = 39966^2 + 8135^2 .

It is a cyclic number.

It is not a de Polignac number, because 1663459381 - 2¹ = 1663459379 is a prime.

It is a super-2 number, since 2×1663459381² = 5534194224473806322, which contains 22 as substring.

Together with 1663459379, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1663459387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 831729690 + 831729691.

It is an arithmetic number, because the mean of its divisors is an integer number (831729691).

Almost surely, 2^1663459381 is an apocalyptic number.

It is an amenable number.

1663459381 is a deficient number, since it is larger than the sum of its proper divisors (1).

1663459381 is an equidigital number, since it uses as much as digits as its factorization.

1663459381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 466560, while the sum is 46.

The square root of 1663459381 is about 40785.5290636275. The cubic root of 1663459381 is about 1184.8700815985.

The spelling of 1663459381 in words is "one billion, six hundred sixty-three million, four hundred fifty-nine thousand, three hundred eighty-one".