640346527 has 2 divisors, whose sum is σ = 640346528. Its totient is φ = 640346526.

The previous prime is 640346503. The next prime is 640346533. The reversal of 640346527 is 725643046.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 640346527 - 2²³ = 631957919 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640346557) 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, 320173263 + 320173264.

It is an arithmetic number, because the mean of its divisors is an integer number (320173264).

Almost surely, 2^640346527 is an apocalyptic number.

640346527 is a deficient number, since it is larger than the sum of its proper divisors (1).

640346527 is an equidigital number, since it uses as much as digits as its factorization.

640346527 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 120960, while the sum is 37.

The square root of 640346527 is about 25305.0691957165. The cubic root of 640346527 is about 861.9293833226.

The spelling of 640346527 in words is "six hundred forty million, three hundred forty-six thousand, five hundred twenty-seven".