643541023 has 2 divisors, whose sum is σ = 643541024. Its totient is φ = 643541022.

The previous prime is 643540991. The next prime is 643541029. The reversal of 643541023 is 320145346.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 643541023 - 2⁵ = 643540991 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 643540982 and 643541000.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643541029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321770511 + 321770512.

It is an arithmetic number, because the mean of its divisors is an integer number (321770512).

Almost surely, 2^643541023 is an apocalyptic number.

643541023 is a deficient number, since it is larger than the sum of its proper divisors (1).

643541023 is an equidigital number, since it uses as much as digits as its factorization.

643541023 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 28.

The square root of 643541023 is about 25368.1103553260. The cubic root of 643541023 is about 863.3603085178.

Adding to 643541023 its reverse (320145346), we get a palindrome (963686369).

The spelling of 643541023 in words is "six hundred forty-three million, five hundred forty-one thousand, twenty-three".