645303236621 has 2 divisors, whose sum is σ = 645303236622. Its totient is φ = 645303236620.

The previous prime is 645303236581. The next prime is 645303236687. The reversal of 645303236621 is 126632303546.

645303236621 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 629263014121 + 16040222500 = 793261^2 + 126650^2 .

It is a cyclic number.

It is not a de Polignac number, because 645303236621 - 2²² = 645299042317 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645303233621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322651618310 + 322651618311.

It is an arithmetic number, because the mean of its divisors is an integer number (322651618311).

Almost surely, 2^645303236621 is an apocalyptic number.

It is an amenable number.

645303236621 is a deficient number, since it is larger than the sum of its proper divisors (1).

645303236621 is an equidigital number, since it uses as much as digits as its factorization.

645303236621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 466560, while the sum is 41.

The spelling of 645303236621 in words is "six hundred forty-five billion, three hundred three million, two hundred thirty-six thousand, six hundred twenty-one".