1666172008 has 8 divisors (see below), whose sum is σ = 3124072530. Its totient is φ = 833086000.

The previous prime is 1666171999. The next prime is 1666172017. The reversal of 1666172008 is 8002716661.

It is an interprime number because it is at equal distance from previous prime (1666171999) and next prime (1666172017).

It can be written as a sum of positive squares in only one way, i.e., 1664476804 + 1695204 = 40798^2 + 1302^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×1666172008² = 5552258320485504128, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104135743 + ... + 104135758.

Almost surely, 2^1666172008 is an apocalyptic number.

It is an amenable number.

1666172008 is a deficient number, since it is larger than the sum of its proper divisors (1457900522).

1666172008 is a wasteful number, since it uses less digits than its factorization.

1666172008 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208271507 (or 208271503 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 1666172008 is about 40818.7702901496. The cubic root of 1666172008 is about 1185.5137933505.

Adding to 1666172008 its reverse (8002716661), we get a palindrome (9668888669).

The spelling of 1666172008 in words is "one billion, six hundred sixty-six million, one hundred seventy-two thousand, eight".