643007969 has 2 divisors, whose sum is σ = 643007970. Its totient is φ = 643007968.

The previous prime is 643007951. The next prime is 643007971. The reversal of 643007969 is 969700346.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 524959744 + 118048225 = 22912^2 + 10865^2 .

It is a cyclic number.

It is not a de Polignac number, because 643007969 - 2¹² = 643003873 is a prime.

It is a super-2 number, since 2×643007969² = 826918496395009922, which contains 22 as substring.

Together with 643007971, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (643007909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321503984 + 321503985.

It is an arithmetic number, because the mean of its divisors is an integer number (321503985).

Almost surely, 2^643007969 is an apocalyptic number.

It is an amenable number.

643007969 is a deficient number, since it is larger than the sum of its proper divisors (1).

643007969 is an equidigital number, since it uses as much as digits as its factorization.

643007969 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 244944, while the sum is 44.

The square root of 643007969 is about 25357.6017990661. The cubic root of 643007969 is about 863.1218648775.

The spelling of 643007969 in words is "six hundred forty-three million, seven thousand, nine hundred sixty-nine".