645593666395546 has 16 divisors (see below), whose sum is σ = 1059008948225280. Its totient is φ = 292734180802080.

The previous prime is 645593666395543. The next prime is 645593666395549.

645593666395546 is nontrivially palindromic in base 10.

It is an interprime number because it is at equal distance from previous prime (645593666395543) and next prime (645593666395549).

It is a self number, because there is not a number n which added to its sum of digits gives 645593666395546.

It is not an unprimeable number, because it can be changed into a prime (645593666395541) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35874277866 + ... + 35874295861.

It is an arithmetic number, because the mean of its divisors is an integer number (66188059264080).

Almost surely, 2^{645593666395546} is an apocalyptic number.

645593666395546 is a deficient number, since it is larger than the sum of its proper divisors (413415281829734).

645593666395546 is a wasteful number, since it uses less digits than its factorization.

645593666395546 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71748574149.

The product of its digits is 56687040000, while the sum is 82.

The spelling of 645593666395546 in words is "six hundred forty-five trillion, five hundred ninety-three billion, six hundred sixty-six million, three hundred ninety-five thousand, five hundred forty-six".