645366989663546 has 8 divisors (see below), whose sum is σ = 968053130157204. Its totient is φ = 322682612944480.

The previous prime is 645366989663507. The next prime is 645366989663567.

645366989663546 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 2 ways, for example, as 609384327575521 + 35982662088025 = 24685711^2 + 5998555^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 440028515 + ... + 441492726.

Almost surely, 2^{645366989663546} is an apocalyptic number.

645366989663546 is a deficient number, since it is larger than the sum of its proper divisors (322686140493658).

645366989663546 is a wasteful number, since it uses less digits than its factorization.

645366989663546 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 881887296.

The product of its digits is 108839116800, while the sum is 86.

The spelling of 645366989663546 in words is "six hundred forty-five trillion, three hundred sixty-six billion, nine hundred eighty-nine million, six hundred sixty-three thousand, five hundred forty-six".