639900269 has 2 divisors, whose sum is σ = 639900270. Its totient is φ = 639900268.

The previous prime is 639900263. The next prime is 639900293. The reversal of 639900269 is 962009936.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 390576169 + 249324100 = 19763^2 + 15790^2 .

It is a cyclic number.

It is not a de Polignac number, because 639900269 - 2⁸ = 639900013 is a prime.

It is a super-2 number, since 2×639900269² = 818944708532544722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (639900263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319950134 + 319950135.

It is an arithmetic number, because the mean of its divisors is an integer number (319950135).

Almost surely, 2^639900269 is an apocalyptic number.

It is an amenable number.

639900269 is a deficient number, since it is larger than the sum of its proper divisors (1).

639900269 is an equidigital number, since it uses as much as digits as its factorization.

639900269 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 157464, while the sum is 44.

The square root of 639900269 is about 25296.2500975935. The cubic root of 639900269 is about 861.7291103695.

The spelling of 639900269 in words is "six hundred thirty-nine million, nine hundred thousand, two hundred sixty-nine".