643717469 has 2 divisors, whose sum is σ = 643717470. Its totient is φ = 643717468.

The previous prime is 643717447. The next prime is 643717483. The reversal of 643717469 is 964717346.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 534765625 + 108951844 = 23125^2 + 10438^2 .

It is a cyclic number.

It is not a de Polignac number, because 643717469 - 2⁸ = 643717213 is a prime.

It is a super-2 number, since 2×643717469² = 828744359791531922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643717429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321858734 + 321858735.

It is an arithmetic number, because the mean of its divisors is an integer number (321858735).

Almost surely, 2^643717469 is an apocalyptic number.

It is an amenable number.

643717469 is a deficient number, since it is larger than the sum of its proper divisors (1).

643717469 is an equidigital number, since it uses as much as digits as its factorization.

643717469 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 762048, while the sum is 47.

The square root of 643717469 is about 25371.5878296964. The cubic root of 643717469 is about 863.4392066492.

The spelling of 643717469 in words is "six hundred forty-three million, seven hundred seventeen thousand, four hundred sixty-nine".