1666720620214 has 64 divisors (see below), whose sum is σ = 2877431155200. Its totient is φ = 717657553152.

The previous prime is 1666720620211. The next prime is 1666720620241. The reversal of 1666720620214 is 4120260276661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666720620211) 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 31 ways as a sum of consecutive naturals, for example, 23151927 + ... + 23223805.

It is an arithmetic number, because the mean of its divisors is an integer number (44959861800).

Almost surely, 2^{1666720620214} is an apocalyptic number.

1666720620214 is a deficient number, since it is larger than the sum of its proper divisors (1210710534986).

1666720620214 is a wasteful number, since it uses less digits than its factorization.

1666720620214 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72629.

The product of its (nonzero) digits is 290304, while the sum is 43.

Adding to 1666720620214 its reverse (4120260276661), we get a palindrome (5786980896875).

The spelling of 1666720620214 in words is "one trillion, six hundred sixty-six billion, seven hundred twenty million, six hundred twenty thousand, two hundred fourteen".