1666211115 has 8 divisors (see below), whose sum is σ = 2665937808. Its totient is φ = 888645920.

The previous prime is 1666211111. The next prime is 1666211159. The reversal of 1666211115 is 5111126661.

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

It is not a de Polignac number, because 1666211115 - 2² = 1666211111 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1666211111) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55540356 + ... + 55540385.

It is an arithmetic number, because the mean of its divisors is an integer number (333242226).

Almost surely, 2^1666211115 is an apocalyptic number.

1666211115 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1666211115 is a deficient number, since it is larger than the sum of its proper divisors (999726693).

1666211115 is a wasteful number, since it uses less digits than its factorization.

1666211115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111080749.

The product of its digits is 2160, while the sum is 30.

The square root of 1666211115 is about 40819.2493194081. The cubic root of 1666211115 is about 1185.5230684083.

Adding to 1666211115 its reverse (5111126661), we get a palindrome (6777337776).

The spelling of 1666211115 in words is "one billion, six hundred sixty-six million, two hundred eleven thousand, one hundred fifteen".