645019 has 2 divisors, whose sum is σ = 645020. Its totient is φ = 645018.

The previous prime is 645013. The next prime is 645023. The reversal of 645019 is 910546.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 645019 - 2³ = 645011 is a prime.

It is a super-2 number, since 2×645019² = 832099020722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 644984 and 645002.

It is not a weakly prime, because it can be changed into another prime (645011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322509 + 322510.

It is an arithmetic number, because the mean of its divisors is an integer number (322510).

2⁶⁴⁵⁰¹⁹ is an apocalyptic number.

645019 is a deficient number, since it is larger than the sum of its proper divisors (1).

645019 is an equidigital number, since it uses as much as digits as its factorization.

645019 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 645019 is about 803.1307490067. The cubic root of 645019 is about 86.4020743529.

The spelling of 645019 in words is "six hundred forty-five thousand, nineteen".