643542607 has 2 divisors, whose sum is σ = 643542608. Its totient is φ = 643542606.

The previous prime is 643542593. The next prime is 643542623. The reversal of 643542607 is 706245346.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 643542607 - 2⁷ = 643542479 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643542637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321771303 + 321771304.

It is an arithmetic number, because the mean of its divisors is an integer number (321771304).

Almost surely, 2^643542607 is an apocalyptic number.

643542607 is a deficient number, since it is larger than the sum of its proper divisors (1).

643542607 is an equidigital number, since it uses as much as digits as its factorization.

643542607 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120960, while the sum is 37.

The square root of 643542607 is about 25368.1415756062. The cubic root of 643542607 is about 863.3610168703.

The spelling of 643542607 in words is "six hundred forty-three million, five hundred forty-two thousand, six hundred seven".