643524031 has 2 divisors, whose sum is σ = 643524032. Its totient is φ = 643524030.

The previous prime is 643524029. The next prime is 643524041. The reversal of 643524031 is 130425346.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 643524031 - 2¹ = 643524029 is a prime.

It is a super-2 number, since 2×643524031² = 828246356948977922, which contains 22 as substring.

Together with 643524029, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643524041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321762015 + 321762016.

It is an arithmetic number, because the mean of its divisors is an integer number (321762016).

Almost surely, 2^643524031 is an apocalyptic number.

643524031 is a deficient number, since it is larger than the sum of its proper divisors (1).

643524031 is an equidigital number, since it uses as much as digits as its factorization.

643524031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 28.

The square root of 643524031 is about 25367.7754444492. The cubic root of 643524031 is about 863.3527097546.

Adding to 643524031 its reverse (130425346), we get a palindrome (773949377).

The spelling of 643524031 in words is "six hundred forty-three million, five hundred twenty-four thousand, thirty-one".