645633343601 has 4 divisors (see below), whose sum is σ = 645646847604. Its totient is φ = 645619839600.

The previous prime is 645633343583. The next prime is 645633343613. The reversal of 645633343601 is 106343336546.

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 294440805376 + 351192538225 = 542624^2 + 592615^2 .

It is a cyclic number.

It is not a de Polignac number, because 645633343601 - 2³⁴ = 628453474417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645633343631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6680030 + ... + 6775991.

It is an arithmetic number, because the mean of its divisors is an integer number (161411711901).

Almost surely, 2^645633343601 is an apocalyptic number.

It is an amenable number.

645633343601 is a deficient number, since it is larger than the sum of its proper divisors (13504003).

645633343601 is a wasteful number, since it uses less digits than its factorization.

645633343601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13504002.

The product of its (nonzero) digits is 1399680, while the sum is 44.

The spelling of 645633343601 in words is "six hundred forty-five billion, six hundred thirty-three million, three hundred forty-three thousand, six hundred one".