640346711 has 2 divisors, whose sum is σ = 640346712. Its totient is φ = 640346710.

The previous prime is 640346627. The next prime is 640346731. The reversal of 640346711 is 117643046.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640346711 is a prime.

It is equal to p_33317717 and since 640346711 and 33317717 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640346731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320173355 + 320173356.

It is an arithmetic number, because the mean of its divisors is an integer number (320173356).

Almost surely, 2^640346711 is an apocalyptic number.

640346711 is a deficient number, since it is larger than the sum of its proper divisors (1).

640346711 is an equidigital number, since it uses as much as digits as its factorization.

640346711 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 32.

The square root of 640346711 is about 25305.0728313514. The cubic root of 640346711 is about 861.9294658795.

Adding to 640346711 its reverse (117643046), we get a palindrome (757989757).

The spelling of 640346711 in words is "six hundred forty million, three hundred forty-six thousand, seven hundred eleven".