643151111 has 2 divisors, whose sum is σ = 643151112. Its totient is φ = 643151110.

The previous prime is 643151071. The next prime is 643151137. The reversal of 643151111 is 111151346.

It is a happy number.

643151111 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-643151111 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643151161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321575555 + 321575556.

It is an arithmetic number, because the mean of its divisors is an integer number (321575556).

Almost surely, 2^643151111 is an apocalyptic number.

643151111 is a deficient number, since it is larger than the sum of its proper divisors (1).

643151111 is an equidigital number, since it uses as much as digits as its factorization.

643151111 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 360, while the sum is 23.

The square root of 643151111 is about 25360.4241092297. The cubic root of 643151111 is about 863.1859075380.

The spelling of 643151111 in words is "six hundred forty-three million, one hundred fifty-one thousand, one hundred eleven".