643627775 has 24 divisors (see below), whose sum is σ = 927080544. Its totient is φ = 434102400.

The previous prime is 643627771. The next prime is 643627801. The reversal of 643627775 is 577726346.

It is not a de Polignac number, because 643627775 - 2² = 643627771 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 (643627771) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19472 + ... + 40821.

It is an arithmetic number, because the mean of its divisors is an integer number (38628356).

Almost surely, 2^643627775 is an apocalyptic number.

643627775 is a deficient number, since it is larger than the sum of its proper divisors (283452769).

643627775 is a wasteful number, since it uses less digits than its factorization.

643627775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60371 (or 60366 counting only the distinct ones).

The product of its digits is 1481760, while the sum is 47.

The square root of 643627775 is about 25369.8201609708. The cubic root of 643627775 is about 863.3991016253.

The spelling of 643627775 in words is "six hundred forty-three million, six hundred twenty-seven thousand, seven hundred seventy-five".