1665711667 has 4 divisors (see below), whose sum is σ = 1666293120. Its totient is φ = 1665130216.

The previous prime is 1665711661. The next prime is 1665711701. The reversal of 1665711667 is 7661175661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7661175661 = 6653 ⋅1151537.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1665711667 is a prime.

It is a super-3 number, since 3×1665711667³ (a number of 29 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1665711661) 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, 286408 + ... + 292165.

It is an arithmetic number, because the mean of its divisors is an integer number (416573280).

Almost surely, 2^1665711667 is an apocalyptic number.

1665711667 is a deficient number, since it is larger than the sum of its proper divisors (581453).

1665711667 is an equidigital number, since it uses as much as digits as its factorization.

1665711667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 581452.

The product of its digits is 317520, while the sum is 46.

The square root of 1665711667 is about 40813.1310609711. The cubic root of 1665711667 is about 1185.4046027686.

The spelling of 1665711667 in words is "one billion, six hundred sixty-five million, seven hundred eleven thousand, six hundred sixty-seven".