3666108991 has 4 divisors (see below), whose sum is σ = 3666977272. Its totient is φ = 3665240712.

The previous prime is 3666108907. The next prime is 3666109003. The reversal of 3666108991 is 1998016663.

3666108991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1998016663 = 1049 ⋅1904687.

It is a cyclic number.

It is not a de Polignac number, because 3666108991 - 2¹³ = 3666100799 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 (3666108791) 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, 427776 + ... + 436261.

It is an arithmetic number, because the mean of its divisors is an integer number (916744318).

Almost surely, 2^3666108991 is an apocalyptic number.

3666108991 is a deficient number, since it is larger than the sum of its proper divisors (868281).

3666108991 is an equidigital number, since it uses as much as digits as its factorization.

3666108991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 868280.

The product of its (nonzero) digits is 419904, while the sum is 49.

The square root of 3666108991 is about 60548.4020515818. The cubic root of 3666108991 is about 1541.9434886763.

The spelling of 3666108991 in words is "three billion, six hundred sixty-six million, one hundred eight thousand, nine hundred ninety-one".