1665551706167 has 4 divisors (see below), whose sum is σ = 1665554311080. Its totient is φ = 1665549101256.

The previous prime is 1665551706113. The next prime is 1665551706173. The reversal of 1665551706167 is 7616071555661.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1665551706167 - 2¹⁰ = 1665551705143 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665551706197) 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, 387809 + ... + 1865877.

It is an arithmetic number, because the mean of its divisors is an integer number (416388577770).

Almost surely, 2^{1665551706167} is an apocalyptic number.

1665551706167 is a deficient number, since it is larger than the sum of its proper divisors (2604913).

1665551706167 is a wasteful number, since it uses less digits than its factorization.

1665551706167 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2604912.

The product of its (nonzero) digits is 7938000, while the sum is 56.

The spelling of 1665551706167 in words is "one trillion, six hundred sixty-five billion, five hundred fifty-one million, seven hundred six thousand, one hundred sixty-seven".