1666557475 has 24 divisors (see below), whose sum is σ = 2260426752. Its totient is φ = 1208800800.

The previous prime is 1666557457. The next prime is 1666557479. The reversal of 1666557475 is 5747556661.

It is not a de Polignac number, because 1666557475 - 2¹⁷ = 1666426403 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1666557479) 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, 97414 + ... + 113236.

It is an arithmetic number, because the mean of its divisors is an integer number (94184448).

Almost surely, 2^1666557475 is an apocalyptic number.

1666557475 is a deficient number, since it is larger than the sum of its proper divisors (593869277).

1666557475 is a wasteful number, since it uses less digits than its factorization.

1666557475 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16227 (or 16222 counting only the distinct ones).

The product of its digits is 5292000, while the sum is 52.

The square root of 1666557475 is about 40823.4917051445. The cubic root of 1666557475 is about 1185.6052087240.

The spelling of 1666557475 in words is "one billion, six hundred sixty-six million, five hundred fifty-seven thousand, four hundred seventy-five".