101666809 has 8 divisors (see below), whose sum is σ = 103921920. Its totient is φ = 99430800.

The previous prime is 101666801. The next prime is 101666821. The reversal of 101666809 is 908666101.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 101666809 - 2³ = 101666801 is a prime.

It is a super-2 number, since 2×101666809² = 20672280104484962, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (101666801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6264 + ... + 15574.

It is an arithmetic number, because the mean of its divisors is an integer number (12990240).

Almost surely, 2^101666809 is an apocalyptic number.

It is an amenable number.

101666809 is a deficient number, since it is larger than the sum of its proper divisors (2255111).

101666809 is an equidigital number, since it uses as much as digits as its factorization.

101666809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9551.

The product of its (nonzero) digits is 15552, while the sum is 37.

The square root of 101666809 is about 10082.9960329259. The cubic root of 101666809 is about 466.7235669281.

The spelling of 101666809 in words is "one hundred one million, six hundred sixty-six thousand, eight hundred nine".