1666115047 has 4 divisors (see below), whose sum is σ = 1723567320. Its totient is φ = 1608662776.

The previous prime is 1666115029. The next prime is 1666115117. The reversal of 1666115047 is 7405116661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7405116661 = 31 ⋅238874731.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1666115047 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1666114997 and 1666115015.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666113047) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28726093 + ... + 28726150.

It is an arithmetic number, because the mean of its divisors is an integer number (430891830).

Almost surely, 2^1666115047 is an apocalyptic number.

1666115047 is a deficient number, since it is larger than the sum of its proper divisors (57452273).

1666115047 is an equidigital number, since it uses as much as digits as its factorization.

1666115047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57452272.

The product of its (nonzero) digits is 30240, while the sum is 37.

The square root of 1666115047 is about 40818.0725537108. The cubic root of 1666115047 is about 1185.5002835767.

The spelling of 1666115047 in words is "one billion, six hundred sixty-six million, one hundred fifteen thousand, forty-seven".