645623605699 has 2 divisors, whose sum is σ = 645623605700. Its totient is φ = 645623605698.

The previous prime is 645623605639. The next prime is 645623605709. The reversal of 645623605699 is 996506326546.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645623605699 is a prime.

It is not a weakly prime, because it can be changed into another prime (645623605639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322811802849 + 322811802850.

It is an arithmetic number, because the mean of its divisors is an integer number (322811802850).

Almost surely, 2^645623605699 is an apocalyptic number.

645623605699 is a deficient number, since it is larger than the sum of its proper divisors (1).

645623605699 is an equidigital number, since it uses as much as digits as its factorization.

645623605699 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 62985600, while the sum is 61.

The spelling of 645623605699 in words is "six hundred forty-five billion, six hundred twenty-three million, six hundred five thousand, six hundred ninety-nine".