639068429 has 2 divisors, whose sum is σ = 639068430. Its totient is φ = 639068428.

The previous prime is 639068413. The next prime is 639068431. The reversal of 639068429 is 924860936.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 519931204 + 119137225 = 22802^2 + 10915^2 .

It is a cyclic number.

It is not a de Polignac number, because 639068429 - 2⁴ = 639068413 is a prime.

Together with 639068431, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (639068459) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319534214 + 319534215.

It is an arithmetic number, because the mean of its divisors is an integer number (319534215).

Almost surely, 2^639068429 is an apocalyptic number.

It is an amenable number.

639068429 is a deficient number, since it is larger than the sum of its proper divisors (1).

639068429 is an equidigital number, since it uses as much as digits as its factorization.

639068429 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 559872, while the sum is 47.

The square root of 639068429 is about 25279.8027879966. The cubic root of 639068429 is about 861.3555461265.

The spelling of 639068429 in words is "six hundred thirty-nine million, sixty-eight thousand, four hundred twenty-nine".