1666550271 has 4 divisors (see below), whose sum is σ = 2222067032. Its totient is φ = 1111033512.

The previous prime is 1666550251. The next prime is 1666550321. The reversal of 1666550271 is 1720556661.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1666550271 - 2¹⁴ = 1666533887 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 (1666550201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 277758376 + ... + 277758381.

It is an arithmetic number, because the mean of its divisors is an integer number (555516758).

Almost surely, 2^1666550271 is an apocalyptic number.

1666550271 is a deficient number, since it is larger than the sum of its proper divisors (555516761).

1666550271 is an equidigital number, since it uses as much as digits as its factorization.

1666550271 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 555516760.

The product of its (nonzero) digits is 75600, while the sum is 39.

The square root of 1666550271 is about 40823.4034715382. The cubic root of 1666550271 is about 1185.6035003897.

The spelling of 1666550271 in words is "one billion, six hundred sixty-six million, five hundred fifty thousand, two hundred seventy-one".