1666665017 has 4 divisors (see below), whose sum is σ = 1668544896. Its totient is φ = 1664785140.

The previous prime is 1666664969. The next prime is 1666665029. The reversal of 1666665017 is 7105666661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 7105666661 = 163 ⋅43593047.

It is a cyclic number.

It is not a de Polignac number, because 1666665017 - 2¹² = 1666660921 is a prime.

It is a super-2 number, since 2×1666665017² = 5555544557783220578, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1666665317) 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, 938609 + ... + 940382.

It is an arithmetic number, because the mean of its divisors is an integer number (417136224).

Almost surely, 2^1666665017 is an apocalyptic number.

It is an amenable number.

1666665017 is a deficient number, since it is larger than the sum of its proper divisors (1879879).

1666665017 is an equidigital number, since it uses as much as digits as its factorization.

1666665017 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1879878.

The product of its (nonzero) digits is 272160, while the sum is 44.

The square root of 1666665017 is about 40824.8088421734. The cubic root of 1666665017 is about 1185.6307103173.

The spelling of 1666665017 in words is "one billion, six hundred sixty-six million, six hundred sixty-five thousand, seventeen".