1666661103 has 20 divisors (see below), whose sum is σ = 2490804360. Its totient is φ = 1110616272.

The previous prime is 1666661099. The next prime is 1666661107. The reversal of 1666661103 is 3011666661.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1666661099) and next prime (1666661107).

It is not a de Polignac number, because 1666661103 - 2² = 1666661099 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666661107) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 339301 + ... + 344177.

It is an arithmetic number, because the mean of its divisors is an integer number (124540218).

Almost surely, 2^1666661103 is an apocalyptic number.

1666661103 is a deficient number, since it is larger than the sum of its proper divisors (824143257).

1666661103 is an equidigital number, since it uses as much as digits as its factorization.

1666661103 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9108 (or 9099 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The square root of 1666661103 is about 40824.7609056073. The cubic root of 1666661103 is about 1185.6297822040.

The spelling of 1666661103 in words is "one billion, six hundred sixty-six million, six hundred sixty-one thousand, one hundred three".