640642234597 has 2 divisors, whose sum is σ = 640642234598. Its totient is φ = 640642234596.

The previous prime is 640642234579. The next prime is 640642234693. The reversal of 640642234597 is 795432246046.

Together with previous prime (640642234579) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 482366364676 + 158275869921 = 694526^2 + 397839^2 .

It is a cyclic number.

It is not a de Polignac number, because 640642234597 - 2⁷ = 640642234469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640642234567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320321117298 + 320321117299.

It is an arithmetic number, because the mean of its divisors is an integer number (320321117299).

Almost surely, 2^640642234597 is an apocalyptic number.

It is an amenable number.

640642234597 is a deficient number, since it is larger than the sum of its proper divisors (1).

640642234597 is an equidigital number, since it uses as much as digits as its factorization.

640642234597 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8709120, while the sum is 52.

The spelling of 640642234597 in words is "six hundred forty billion, six hundred forty-two million, two hundred thirty-four thousand, five hundred ninety-seven".