643417331 has 2 divisors, whose sum is σ = 643417332. Its totient is φ = 643417330.

The previous prime is 643417319. The next prime is 643417337. The reversal of 643417331 is 133714346.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 643417331 - 2²² = 639223027 is a prime.

It is a super-2 number, since 2×643417331² = 827971723662327122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (643417337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321708665 + 321708666.

It is an arithmetic number, because the mean of its divisors is an integer number (321708666).

Almost surely, 2^643417331 is an apocalyptic number.

643417331 is a deficient number, since it is larger than the sum of its proper divisors (1).

643417331 is an equidigital number, since it uses as much as digits as its factorization.

643417331 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18144, while the sum is 32.

The square root of 643417331 is about 25365.6722954469. The cubic root of 643417331 is about 863.3049908291.

The spelling of 643417331 in words is "six hundred forty-three million, four hundred seventeen thousand, three hundred thirty-one".