1663671631 has 8 divisors (see below), whose sum is σ = 1681229520. Its totient is φ = 1646151168.

The previous prime is 1663671593. The next prime is 1663671649. The reversal of 1663671631 is 1361763661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1663671631 - 2²¹ = 1661574479 is a prime.

It is a super-3 number, since 3×1663671631³ (a number of 29 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1663671131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84975 + ... + 102703.

It is an arithmetic number, because the mean of its divisors is an integer number (210153690).

Almost surely, 2^1663671631 is an apocalyptic number.

1663671631 is a deficient number, since it is larger than the sum of its proper divisors (17557889).

1663671631 is a wasteful number, since it uses less digits than its factorization.

1663671631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18713.

The product of its digits is 81648, while the sum is 40.

The square root of 1663671631 is about 40788.1310064582. The cubic root of 1663671631 is about 1184.9204741684.

The spelling of 1663671631 in words is "one billion, six hundred sixty-three million, six hundred seventy-one thousand, six hundred thirty-one".