645453373 has 2 divisors, whose sum is σ = 645453374. Its totient is φ = 645453372.

The previous prime is 645453353. The next prime is 645453469. The reversal of 645453373 is 373354546.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 640950489 + 4502884 = 25317^2 + 2122^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645453373 is a prime.

It is a super-2 number, since 2×645453373² = 833220113434154258, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645453343) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322726686 + 322726687.

It is an arithmetic number, because the mean of its divisors is an integer number (322726687).

Almost surely, 2^645453373 is an apocalyptic number.

It is an amenable number.

645453373 is a deficient number, since it is larger than the sum of its proper divisors (1).

645453373 is an equidigital number, since it uses as much as digits as its factorization.

645453373 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 453600, while the sum is 40.

The square root of 645453373 is about 25405.7744026826. The cubic root of 645453373 is about 864.2146515467.

The spelling of 645453373 in words is "six hundred forty-five million, four hundred fifty-three thousand, three hundred seventy-three".