645848549 has 2 divisors, whose sum is σ = 645848550. Its totient is φ = 645848548.

The previous prime is 645848537. The next prime is 645848569. The reversal of 645848549 is 945848546.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 610979524 + 34869025 = 24718^2 + 5905^2 .

It is a cyclic number.

It is not a de Polignac number, because 645848549 - 2⁸ = 645848293 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 645848549.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645848569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322924274 + 322924275.

It is an arithmetic number, because the mean of its divisors is an integer number (322924275).

Almost surely, 2^645848549 is an apocalyptic number.

It is an amenable number.

645848549 is a deficient number, since it is larger than the sum of its proper divisors (1).

645848549 is an equidigital number, since it uses as much as digits as its factorization.

645848549 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5529600, while the sum is 53.

The square root of 645848549 is about 25413.5504996842. The cubic root of 645848549 is about 864.3909861097.

The spelling of 645848549 in words is "six hundred forty-five million, eight hundred forty-eight thousand, five hundred forty-nine".