6640523387 has 2 divisors, whose sum is σ = 6640523388. Its totient is φ = 6640523386.

The previous prime is 6640523381. The next prime is 6640523507. The reversal of 6640523387 is 7833250466.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6640523387 - 2²⁰ = 6639474811 is a prime.

It is not a weakly prime, because it can be changed into another prime (6640523381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3320261693 + 3320261694.

It is an arithmetic number, because the mean of its divisors is an integer number (3320261694).

Almost surely, 2^6640523387 is an apocalyptic number.

6640523387 is a deficient number, since it is larger than the sum of its proper divisors (1).

6640523387 is an equidigital number, since it uses as much as digits as its factorization.

6640523387 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 725760, while the sum is 44.

The square root of 6640523387 is about 81489.4065937408. The cubic root of 6640523387 is about 1879.6086580751.

The spelling of 6640523387 in words is "six billion, six hundred forty million, five hundred twenty-three thousand, three hundred eighty-seven".