643723 has 2 divisors, whose sum is σ = 643724. Its totient is φ = 643722.

The previous prime is 643703. The next prime is 643729. The reversal of 643723 is 327346.

643723 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 not a de Polignac number, because 643723 - 2⁵ = 643691 is a prime.

It is a d-powerful number, because it can be written as 6⁶ + 4⁸ + 7 + 3⁴ + 2 + 3¹² .

It is not a weakly prime, because it can be changed into another prime (643729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321861 + 321862.

It is an arithmetic number, because the mean of its divisors is an integer number (321862).

2⁶⁴³⁷²³ is an apocalyptic number.

643723 is a deficient number, since it is larger than the sum of its proper divisors (1).

643723 is an equidigital number, since it uses as much as digits as its factorization.

643723 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 25.

The square root of 643723 is about 802.3235008399. The cubic root of 643723 is about 86.3441679612.

The spelling of 643723 in words is "six hundred forty-three thousand, seven hundred twenty-three".