639970229 has 2 divisors, whose sum is σ = 639970230. Its totient is φ = 639970228.

The previous prime is 639970223. The next prime is 639970267. The reversal of 639970229 is 922079936.

639970229 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 488631025 + 151339204 = 22105^2 + 12302^2 .

It is a cyclic number.

It is not a de Polignac number, because 639970229 - 2²⁴ = 623193013 is a prime.

It is equal to p_33298967 and since 639970229 and 33298967 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (639970223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319985114 + 319985115.

It is an arithmetic number, because the mean of its divisors is an integer number (319985115).

Almost surely, 2^639970229 is an apocalyptic number.

It is an amenable number.

639970229 is a deficient number, since it is larger than the sum of its proper divisors (1).

639970229 is an equidigital number, since it uses as much as digits as its factorization.

639970229 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 367416, while the sum is 47.

The square root of 639970229 is about 25297.6328734528. The cubic root of 639970229 is about 861.7605133732.

The spelling of 639970229 in words is "six hundred thirty-nine million, nine hundred seventy thousand, two hundred twenty-nine".