640606039 has 2 divisors, whose sum is σ = 640606040. Its totient is φ = 640606038.

The previous prime is 640606037. The next prime is 640606063. The reversal of 640606039 is 930606046.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 640606039 - 2¹ = 640606037 is a prime.

Together with 640606037, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 640605995 and 640606013.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640606037) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320303019 + 320303020.

It is an arithmetic number, because the mean of its divisors is an integer number (320303020).

Almost surely, 2^640606039 is an apocalyptic number.

640606039 is a deficient number, since it is larger than the sum of its proper divisors (1).

640606039 is an equidigital number, since it uses as much as digits as its factorization.

640606039 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23328, while the sum is 34.

The square root of 640606039 is about 25310.1963445565. The cubic root of 640606039 is about 862.0458050821.

The spelling of 640606039 in words is "six hundred forty million, six hundred six thousand, thirty-nine".