640140643403 has 2 divisors, whose sum is σ = 640140643404. Its totient is φ = 640140643402.

The previous prime is 640140643399. The next prime is 640140643463. The reversal of 640140643403 is 304346041046.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 640140643403 - 2² = 640140643399 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (640140643463) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320070321701 + 320070321702.

It is an arithmetic number, because the mean of its divisors is an integer number (320070321702).

Almost surely, 2^640140643403 is an apocalyptic number.

640140643403 is a deficient number, since it is larger than the sum of its proper divisors (1).

640140643403 is an equidigital number, since it uses as much as digits as its factorization.

640140643403 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 82944, while the sum is 35.

Adding to 640140643403 its reverse (304346041046), we get a palindrome (944486684449).

It can be divided in two parts, 640140643 and 403, that added together give a palindrome (640141046).

The spelling of 640140643403 in words is "six hundred forty billion, one hundred forty million, six hundred forty-three thousand, four hundred three".