643122499 has 2 divisors, whose sum is σ = 643122500. Its totient is φ = 643122498.

The previous prime is 643122443. The next prime is 643122509. The reversal of 643122499 is 994221346.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 643122499 - 2⁷ = 643122371 is a prime.

It is not a weakly prime, because it can be changed into another prime (643125499) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321561249 + 321561250.

It is an arithmetic number, because the mean of its divisors is an integer number (321561250).

Almost surely, 2^643122499 is an apocalyptic number.

643122499 is a deficient number, since it is larger than the sum of its proper divisors (1).

643122499 is an equidigital number, since it uses as much as digits as its factorization.

643122499 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 93312, while the sum is 40.

The square root of 643122499 is about 25359.8599956703. The cubic root of 643122499 is about 863.1731071033.

The spelling of 643122499 in words is "six hundred forty-three million, one hundred twenty-two thousand, four hundred ninety-nine".