1663691071 has 12 divisors (see below), whose sum is σ = 1982519280. Its totient is φ = 1391238240.

The previous prime is 1663691063. The next prime is 1663691191. The reversal of 1663691071 is 1701963661.

It is not a de Polignac number, because 1663691071 - 2³ = 1663691063 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1663691021) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 412051 + ... + 416068.

It is an arithmetic number, because the mean of its divisors is an integer number (165209940).

Almost surely, 2^1663691071 is an apocalyptic number.

1663691071 is a deficient number, since it is larger than the sum of its proper divisors (318828209).

1663691071 is an equidigital number, since it uses as much as digits as its factorization.

1663691071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 828174 (or 828167 counting only the distinct ones).

The product of its (nonzero) digits is 40824, while the sum is 40.

The square root of 1663691071 is about 40788.3693103806. The cubic root of 1663691071 is about 1184.9250894150.

The spelling of 1663691071 in words is "one billion, six hundred sixty-three million, six hundred ninety-one thousand, seventy-one".