1665466026401 has 4 divisors (see below), whose sum is σ = 1665476778900. Its totient is φ = 1665455273904.

The previous prime is 1665466026377. The next prime is 1665466026403. The reversal of 1665466026401 is 1046206645661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1265535001600 + 399931024801 = 1124960^2 + 632401^2 .

It is a cyclic number.

It is not a de Polignac number, because 1665466026401 - 2¹⁸ = 1665465764257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1665466026403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5140466 + ... + 5454843.

It is an arithmetic number, because the mean of its divisors is an integer number (416369194725).

Almost surely, 2^{1665466026401} is an apocalyptic number.

It is an amenable number.

1665466026401 is a deficient number, since it is larger than the sum of its proper divisors (10752499).

1665466026401 is a wasteful number, since it uses less digits than its factorization.

1665466026401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10752498.

The product of its (nonzero) digits is 1244160, while the sum is 47.

The spelling of 1665466026401 in words is "one trillion, six hundred sixty-five billion, four hundred sixty-six million, twenty-six thousand, four hundred one".