640202689547 has 2 divisors, whose sum is σ = 640202689548. Its totient is φ = 640202689546.

The previous prime is 640202689471. The next prime is 640202689559. The reversal of 640202689547 is 745986202046.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 640202689547 - 2²² = 640198495243 is a prime.

It is not a weakly prime, because it can be changed into another prime (640202680547) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320101344773 + 320101344774.

It is an arithmetic number, because the mean of its divisors is an integer number (320101344774).

Almost surely, 2^640202689547 is an apocalyptic number.

640202689547 is a deficient number, since it is larger than the sum of its proper divisors (1).

640202689547 is an equidigital number, since it uses as much as digits as its factorization.

640202689547 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5806080, while the sum is 53.

The spelling of 640202689547 in words is "six hundred forty billion, two hundred two million, six hundred eighty-nine thousand, five hundred forty-seven".