108211661 has 4 divisors (see below), whose sum is σ = 108245052. Its totient is φ = 108178272.

The previous prime is 108211627. The next prime is 108211679. The reversal of 108211661 is 166112801.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 166112801 = 19 ⋅8742779.

It can be written as a sum of positive squares in 2 ways, for example, as 54834025 + 53377636 = 7405^2 + 7306^2 .

It is a cyclic number.

It is not a de Polignac number, because 108211661 - 2¹⁰ = 108210637 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 108211661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (108211261) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11240 + ... + 18513.

It is an arithmetic number, because the mean of its divisors is an integer number (27061263).

Almost surely, 2^108211661 is an apocalyptic number.

It is an amenable number.

108211661 is a deficient number, since it is larger than the sum of its proper divisors (33391).

108211661 is an equidigital number, since it uses as much as digits as its factorization.

108211661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33390.

The product of its (nonzero) digits is 576, while the sum is 26.

The square root of 108211661 is about 10402.4834054182. The cubic root of 108211661 is about 476.5312152556.

The spelling of 108211661 in words is "one hundred eight million, two hundred eleven thousand, six hundred sixty-one".