643415441 has 2 divisors, whose sum is σ = 643415442. Its totient is φ = 643415440.

The previous prime is 643415393. The next prime is 643415467. The reversal of 643415441 is 144514346.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 633780625 + 9634816 = 25175^2 + 3104^2 .

It is a cyclic number.

It is not a de Polignac number, because 643415441 - 2¹⁸ = 643153297 is a prime.

It is a super-3 number, since 3×643415441³ (a number of 27 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 643415398 and 643415407.

It is not a weakly prime, because it can be changed into another prime (643415471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321707720 + 321707721.

It is an arithmetic number, because the mean of its divisors is an integer number (321707721).

Almost surely, 2^643415441 is an apocalyptic number.

It is an amenable number.

643415441 is a deficient number, since it is larger than the sum of its proper divisors (1).

643415441 is an equidigital number, since it uses as much as digits as its factorization.

643415441 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23040, while the sum is 32.

The square root of 643415441 is about 25365.6350403454. The cubic root of 643415441 is about 863.3041455260.

Adding to 643415441 its reverse (144514346), we get a palindrome (787929787).

The spelling of 643415441 in words is "six hundred forty-three million, four hundred fifteen thousand, four hundred forty-one".