1663638271 has 8 divisors (see below), whose sum is σ = 1752088320. Its totient is φ = 1575277272.

The previous prime is 1663638257. The next prime is 1663638287. The reversal of 1663638271 is 1728363661.

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 1663638271 - 2⁵ = 1663638239 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1663638211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17976 + ... + 60418.

It is an arithmetic number, because the mean of its divisors is an integer number (219011040).

Almost surely, 2^1663638271 is an apocalyptic number.

1663638271 is a deficient number, since it is larger than the sum of its proper divisors (88450049).

1663638271 is a wasteful number, since it uses less digits than its factorization.

1663638271 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44525.

The product of its digits is 217728, while the sum is 43.

The square root of 1663638271 is about 40787.7220619147. The cubic root of 1663638271 is about 1184.9125540936.

The spelling of 1663638271 in words is "one billion, six hundred sixty-three million, six hundred thirty-eight thousand, two hundred seventy-one".