645775087 has 2 divisors, whose sum is σ = 645775088. Its totient is φ = 645775086.

The previous prime is 645775079. The next prime is 645775121. The reversal of 645775087 is 780577546.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 645775087 - 2³ = 645775079 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 645775087.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645775007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322887543 + 322887544.

It is an arithmetic number, because the mean of its divisors is an integer number (322887544).

Almost surely, 2^645775087 is an apocalyptic number.

645775087 is a deficient number, since it is larger than the sum of its proper divisors (1).

645775087 is an equidigital number, since it uses as much as digits as its factorization.

645775087 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1646400, while the sum is 49.

The square root of 645775087 is about 25412.1051272814. The cubic root of 645775087 is about 864.3582115021.

The spelling of 645775087 in words is "six hundred forty-five million, seven hundred seventy-five thousand, eighty-seven".