1665266537805 has 64 divisors (see below), whose sum is σ = 3056363186688. Its totient is φ = 766978007040.

The previous prime is 1665266537783. The next prime is 1665266537821. The reversal of 1665266537805 is 5087356625661.

It is not a de Polignac number, because 1665266537805 - 2⁸ = 1665266537549 is a prime.

It is a super-2 number, since 2×1665266537805² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 950416 + ... + 2057625.

It is an arithmetic number, because the mean of its divisors is an integer number (47755674792).

Almost surely, 2^{1665266537805} is an apocalyptic number.

1665266537805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1665266537805 is a deficient number, since it is larger than the sum of its proper divisors (1391096648883).

1665266537805 is a wasteful number, since it uses less digits than its factorization.

1665266537805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3008246.

The product of its (nonzero) digits is 54432000, while the sum is 60.

The spelling of 1665266537805 in words is "one trillion, six hundred sixty-five billion, two hundred sixty-six million, five hundred thirty-seven thousand, eight hundred five".