645858454309 has 2 divisors, whose sum is σ = 645858454310. Its totient is φ = 645858454308.

The previous prime is 645858454301. The next prime is 645858454321. The reversal of 645858454309 is 903454858546.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 381055586209 + 264802868100 = 617297^2 + 514590^2 .

It is a cyclic number.

It is not a de Polignac number, because 645858454309 - 2³ = 645858454301 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645858454301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322929227154 + 322929227155.

It is an arithmetic number, because the mean of its divisors is an integer number (322929227155).

Almost surely, 2^645858454309 is an apocalyptic number.

It is an amenable number.

645858454309 is a deficient number, since it is larger than the sum of its proper divisors (1).

645858454309 is an equidigital number, since it uses as much as digits as its factorization.

645858454309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 82944000, while the sum is 61.

The spelling of 645858454309 in words is "six hundred forty-five billion, eight hundred fifty-eight million, four hundred fifty-four thousand, three hundred nine".