639833 has 2 divisors, whose sum is σ = 639834. Its totient is φ = 639832.

The previous prime is 639757. The next prime is 639839. The reversal of 639833 is 338936.

It is a happy number.

639833 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 can be written as a sum of positive squares in only one way, i.e., 635209 + 4624 = 797^2 + 68^2 .

It is a cyclic number.

It is not a de Polignac number, because 639833 - 2⁸ = 639577 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 639833.

It is not a weakly prime, because it can be changed into another prime (639839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319916 + 319917.

It is an arithmetic number, because the mean of its divisors is an integer number (319917).

2⁶³⁹⁸³³ is an apocalyptic number.

It is an amenable number.

639833 is a deficient number, since it is larger than the sum of its proper divisors (1).

639833 is an equidigital number, since it uses as much as digits as its factorization.

639833 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11664, while the sum is 32.

The square root of 639833 is about 799.8956181903. The cubic root of 639833 is about 86.1698913119.

The spelling of 639833 in words is "six hundred thirty-nine thousand, eight hundred thirty-three".