1666671291 has 24 divisors (see below), whose sum is σ = 2440279296. Its totient is φ = 1095989040.

The previous prime is 1666671283. The next prime is 1666671311. The reversal of 1666671291 is 1921766661.

It is not a de Polignac number, because 1666671291 - 2³ = 1666671283 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1666671091) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 613426 + ... + 616136.

It is an arithmetic number, because the mean of its divisors is an integer number (101678304).

Almost surely, 2^1666671291 is an apocalyptic number.

1666671291 is a deficient number, since it is larger than the sum of its proper divisors (773608005).

1666671291 is a wasteful number, since it uses less digits than its factorization.

1666671291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3623 (or 3620 counting only the distinct ones).

The product of its digits is 163296, while the sum is 45.

The square root of 1666671291 is about 40824.8856826324. The cubic root of 1666671291 is about 1185.6321980464.

The spelling of 1666671291 in words is "one billion, six hundred sixty-six million, six hundred seventy-one thousand, two hundred ninety-one".