643106331 has 48 divisors (see below), whose sum is σ = 1113451680. Its totient is φ = 365783040.

The previous prime is 643106297. The next prime is 643106371. The reversal of 643106331 is 133601346.

643106331 is a `hidden beast` number, since 643 + 10 + 6 + 3 + 3 + 1 = 666.

It is not a de Polignac number, because 643106331 - 2⁷ = 643106203 is a prime.

It is a super-2 number, since 2×643106331² = 827171505944563122, which contains 22 as substring.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 643106295 and 643106304.

It is not an unprimeable number, because it can be changed into a prime (643106371) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 317835 + ... + 319851.

It is an arithmetic number, because the mean of its divisors is an integer number (23196910).

Almost surely, 2^643106331 is an apocalyptic number.

643106331 is a deficient number, since it is larger than the sum of its proper divisors (470345349).

643106331 is a wasteful number, since it uses less digits than its factorization.

643106331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2281 (or 2268 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 27.

The square root of 643106331 is about 25359.5412221909. The cubic root of 643106331 is about 863.1658736966.

Adding to 643106331 its reverse (133601346), we get a palindrome (776707677).

The spelling of 643106331 in words is "six hundred forty-three million, one hundred six thousand, three hundred thirty-one".