645813053 has 2 divisors, whose sum is σ = 645813054. Its totient is φ = 645813052.

The previous prime is 645813023. The next prime is 645813061. The reversal of 645813053 is 350318546.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 416078404 + 229734649 = 20398^2 + 15157^2 .

It is a cyclic number.

It is not a de Polignac number, because 645813053 - 2²⁴ = 629035837 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645813013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322906526 + 322906527.

It is an arithmetic number, because the mean of its divisors is an integer number (322906527).

Almost surely, 2^645813053 is an apocalyptic number.

It is an amenable number.

645813053 is a deficient number, since it is larger than the sum of its proper divisors (1).

645813053 is an equidigital number, since it uses as much as digits as its factorization.

645813053 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 43200, while the sum is 35.

The square root of 645813053 is about 25412.8521224990. The cubic root of 645813053 is about 864.3751501037.

The spelling of 645813053 in words is "six hundred forty-five million, eight hundred thirteen thousand, fifty-three".