845605639 has 2 divisors, whose sum is σ = 845605640. Its totient is φ = 845605638.

The previous prime is 845605627. The next prime is 845605667. The reversal of 845605639 is 936506548.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-845605639 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (845605679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 422802819 + 422802820.

It is an arithmetic number, because the mean of its divisors is an integer number (422802820).

Almost surely, 2^845605639 is an apocalyptic number.

845605639 is a deficient number, since it is larger than the sum of its proper divisors (1).

845605639 is an equidigital number, since it uses as much as digits as its factorization.

845605639 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 777600, while the sum is 46.

The square root of 845605639 is about 29079.2991490510. The cubic root of 845605639 is about 945.6330086921.

Subtracting 845605639 from its reverse (936506548), we obtain a palindrome (90900909).

The spelling of 845605639 in words is "eight hundred forty-five million, six hundred five thousand, six hundred thirty-nine".