645065616577 has 2 divisors, whose sum is σ = 645065616578. Its totient is φ = 645065616576.

The previous prime is 645065616491. The next prime is 645065616619. The reversal of 645065616577 is 775616560546.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 595352671281 + 49712945296 = 771591^2 + 222964^2 .

It is a cyclic number.

It is not a de Polignac number, because 645065616577 - 2²⁷ = 644931398849 is a prime.

It is a super-2 number, since 2×645065616577² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (645065616677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322532808288 + 322532808289.

It is an arithmetic number, because the mean of its divisors is an integer number (322532808289).

Almost surely, 2^645065616577 is an apocalyptic number.

It is an amenable number.

645065616577 is a deficient number, since it is larger than the sum of its proper divisors (1).

645065616577 is an equidigital number, since it uses as much as digits as its factorization.

645065616577 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31752000, while the sum is 58.

The spelling of 645065616577 in words is "six hundred forty-five billion, sixty-five million, six hundred sixteen thousand, five hundred seventy-seven".