640103251 has 2 divisors, whose sum is σ = 640103252. Its totient is φ = 640103250.

The previous prime is 640103249. The next prime is 640103257. The reversal of 640103251 is 152301046.

640103251 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 is a cyclic number.

It is not a de Polignac number, because 640103251 - 2¹ = 640103249 is a prime.

Together with 640103249, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (640103257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320051625 + 320051626.

It is an arithmetic number, because the mean of its divisors is an integer number (320051626).

Almost surely, 2^640103251 is an apocalyptic number.

640103251 is a deficient number, since it is larger than the sum of its proper divisors (1).

640103251 is an equidigital number, since it uses as much as digits as its factorization.

640103251 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 640103251 is about 25300.2618761150. The cubic root of 640103251 is about 861.8202167575.

Adding to 640103251 its reverse (152301046), we get a palindrome (792404297).

The spelling of 640103251 in words is "six hundred forty million, one hundred three thousand, two hundred fifty-one".