639950089 has 2 divisors, whose sum is σ = 639950090. Its totient is φ = 639950088.

The previous prime is 639950071. The next prime is 639950107. The reversal of 639950089 is 980059936.

It is a balanced prime because it is at equal distance from previous prime (639950071) and next prime (639950107).

It can be written as a sum of positive squares in only one way, i.e., 618019600 + 21930489 = 24860^2 + 4683^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-639950089 is a prime.

It is a super-2 number, since 2×639950089² = 819072232822215842, which contains 22 as substring.

It is equal to p_33297979 and since 639950089 and 33297979 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (639950029) 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, 319975044 + 319975045.

It is an arithmetic number, because the mean of its divisors is an integer number (319975045).

Almost surely, 2^639950089 is an apocalyptic number.

It is an amenable number.

639950089 is a deficient number, since it is larger than the sum of its proper divisors (1).

639950089 is an equidigital number, since it uses as much as digits as its factorization.

639950089 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 524880, while the sum is 49.

The square root of 639950089 is about 25297.2348093621. The cubic root of 639950089 is about 861.7514733492.

The spelling of 639950089 in words is "six hundred thirty-nine million, nine hundred fifty thousand, eighty-nine".