643622099 has 2 divisors, whose sum is σ = 643622100. Its totient is φ = 643622098.

The previous prime is 643622081. The next prime is 643622113. The reversal of 643622099 is 990226346.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 643622099 - 2⁸ = 643621843 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (643622009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321811049 + 321811050.

It is an arithmetic number, because the mean of its divisors is an integer number (321811050).

Almost surely, 2^643622099 is an apocalyptic number.

643622099 is a deficient number, since it is larger than the sum of its proper divisors (1).

643622099 is an equidigital number, since it uses as much as digits as its factorization.

643622099 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 139968, while the sum is 41.

The square root of 643622099 is about 25369.7082955244. The cubic root of 643622099 is about 863.3965635808.

The spelling of 643622099 in words is "six hundred forty-three million, six hundred twenty-two thousand, ninety-nine".