643252541 has 2 divisors, whose sum is σ = 643252542. Its totient is φ = 643252540.

The previous prime is 643252471. The next prime is 643252583. The reversal of 643252541 is 145252346.

643252541 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 588062500 + 55190041 = 24250^2 + 7429^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-643252541 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 643252498 and 643252507.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643254541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321626270 + 321626271.

It is an arithmetic number, because the mean of its divisors is an integer number (321626271).

Almost surely, 2^643252541 is an apocalyptic number.

It is an amenable number.

643252541 is a deficient number, since it is larger than the sum of its proper divisors (1).

643252541 is an equidigital number, since it uses as much as digits as its factorization.

643252541 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 28800, while the sum is 32.

The square root of 643252541 is about 25362.4237997870. The cubic root of 643252541 is about 863.2312822268.

It can be divided in two parts, 64325 and 2541, that added together give a palindrome (66866).

The spelling of 643252541 in words is "six hundred forty-three million, two hundred fifty-two thousand, five hundred forty-one".