645089189 has 2 divisors, whose sum is σ = 645089190. Its totient is φ = 645089188.

The previous prime is 645089167. The next prime is 645089201. The reversal of 645089189 is 981980546.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 456164164 + 188925025 = 21358^2 + 13745^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645089189 is a prime.

It is a super-2 number, since 2×645089189² = 832280123529355442, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645089989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322544594 + 322544595.

It is an arithmetic number, because the mean of its divisors is an integer number (322544595).

Almost surely, 2^645089189 is an apocalyptic number.

It is an amenable number.

645089189 is a deficient number, since it is larger than the sum of its proper divisors (1).

645089189 is an equidigital number, since it uses as much as digits as its factorization.

645089189 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 622080, while the sum is 50.

The square root of 645089189 is about 25398.6060444269. The cubic root of 645089189 is about 864.0520824264.

The spelling of 645089189 in words is "six hundred forty-five million, eighty-nine thousand, one hundred eighty-nine".