645857699 has 2 divisors, whose sum is σ = 645857700. Its totient is φ = 645857698.

The previous prime is 645857657. The next prime is 645857701. The reversal of 645857699 is 996758546.

645857699 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645857699 is a prime.

Together with 645857701, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (645857609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322928849 + 322928850.

It is an arithmetic number, because the mean of its divisors is an integer number (322928850).

Almost surely, 2^645857699 is an apocalyptic number.

645857699 is a deficient number, since it is larger than the sum of its proper divisors (1).

645857699 is an equidigital number, since it uses as much as digits as its factorization.

645857699 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16329600, while the sum is 59.

The square root of 645857699 is about 25413.7305211179. The cubic root of 645857699 is about 864.3950681504.

The spelling of 645857699 in words is "six hundred forty-five million, eight hundred fifty-seven thousand, six hundred ninety-nine".