643632255 has 24 divisors (see below), whose sum is σ = 1275005472. Its totient is φ = 294231744.

The previous prime is 643632251. The next prime is 643632259. The reversal of 643632255 is 552236346.

643632255 is a `hidden beast` number, since 643 + 6 + 3 + 2 + 2 + 5 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (643632251) and next prime (643632259).

It is not a de Polignac number, because 643632255 - 2² = 643632251 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643632251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1021324 + ... + 1021953.

It is an arithmetic number, because the mean of its divisors is an integer number (53125228).

Almost surely, 2^643632255 is an apocalyptic number.

643632255 is a deficient number, since it is larger than the sum of its proper divisors (631373217).

643632255 is a wasteful number, since it uses less digits than its factorization.

643632255 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2043295 (or 2043292 counting only the distinct ones).

The product of its digits is 129600, while the sum is 36.

The square root of 643632255 is about 25369.9084547028. The cubic root of 643632255 is about 863.4011048633.

The spelling of 643632255 in words is "six hundred forty-three million, six hundred thirty-two thousand, two hundred fifty-five".