643319623 has 2 divisors, whose sum is σ = 643319624. Its totient is φ = 643319622.

The previous prime is 643319519. The next prime is 643319641. The reversal of 643319623 is 326913346.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 643319623 - 2²¹ = 641222471 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643319653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321659811 + 321659812.

It is an arithmetic number, because the mean of its divisors is an integer number (321659812).

Almost surely, 2^643319623 is an apocalyptic number.

643319623 is a deficient number, since it is larger than the sum of its proper divisors (1).

643319623 is an equidigital number, since it uses as much as digits as its factorization.

643319623 is an evil number, because the sum of its binary digits is even.

The product of its digits is 69984, while the sum is 37.

The square root of 643319623 is about 25363.7462335515. The cubic root of 643319623 is about 863.2612887246.

The spelling of 643319623 in words is "six hundred forty-three million, three hundred nineteen thousand, six hundred twenty-three".