645688452839 has 32 divisors (see below), whose sum is σ = 733253160960. Its totient is φ = 565343539200.

The previous prime is 645688452803. The next prime is 645688452859. The reversal of 645688452839 is 938254886546.

It is a happy number.

It is not a de Polignac number, because 645688452839 - 2³² = 641393485543 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645688452859) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8646449 + ... + 8720805.

It is an arithmetic number, because the mean of its divisors is an integer number (22914161280).

Almost surely, 2^645688452839 is an apocalyptic number.

645688452839 is a deficient number, since it is larger than the sum of its proper divisors (87564708121).

645688452839 is a wasteful number, since it uses less digits than its factorization.

645688452839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75071.

The product of its digits is 398131200, while the sum is 68.

The spelling of 645688452839 in words is "six hundred forty-five billion, six hundred eighty-eight million, four hundred fifty-two thousand, eight hundred thirty-nine".