645270206549 has 2 divisors, whose sum is σ = 645270206550. Its totient is φ = 645270206548.

The previous prime is 645270206519. The next prime is 645270206573. The reversal of 645270206549 is 945602072546.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 605112852100 + 40157354449 = 777890^2 + 200393^2 .

It is a cyclic number.

It is not a de Polignac number, because 645270206549 - 2³⁶ = 576550729813 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 645270206497 and 645270206506.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645270206519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322635103274 + 322635103275.

It is an arithmetic number, because the mean of its divisors is an integer number (322635103275).

Almost surely, 2^645270206549 is an apocalyptic number.

It is an amenable number.

645270206549 is a deficient number, since it is larger than the sum of its proper divisors (1).

645270206549 is an equidigital number, since it uses as much as digits as its factorization.

645270206549 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3628800, while the sum is 50.

The spelling of 645270206549 in words is "six hundred forty-five billion, two hundred seventy million, two hundred six thousand, five hundred forty-nine".