645308941 has 2 divisors, whose sum is σ = 645308942. Its totient is φ = 645308940.

The previous prime is 645308921. The next prime is 645309043. The reversal of 645308941 is 149803546.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 493772841 + 151536100 = 22221^2 + 12310^2 .

It is a cyclic number.

It is not a de Polignac number, because 645308941 - 2¹³ = 645300749 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 645308894 and 645308903.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645308921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322654470 + 322654471.

It is an arithmetic number, because the mean of its divisors is an integer number (322654471).

Almost surely, 2^645308941 is an apocalyptic number.

It is an amenable number.

645308941 is a deficient number, since it is larger than the sum of its proper divisors (1).

645308941 is an equidigital number, since it uses as much as digits as its factorization.

645308941 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 103680, while the sum is 40.

The square root of 645308941 is about 25402.9317402539. The cubic root of 645308941 is about 864.1501854586.

The spelling of 645308941 in words is "six hundred forty-five million, three hundred eight thousand, nine hundred forty-one".