645509087 has 2 divisors, whose sum is σ = 645509088. Its totient is φ = 645509086.

The previous prime is 645509083. The next prime is 645509113. The reversal of 645509087 is 780905546.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 645509087 - 2² = 645509083 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645509083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322754543 + 322754544.

It is an arithmetic number, because the mean of its divisors is an integer number (322754544).

Almost surely, 2^645509087 is an apocalyptic number.

645509087 is a deficient number, since it is larger than the sum of its proper divisors (1).

645509087 is an equidigital number, since it uses as much as digits as its factorization.

645509087 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 302400, while the sum is 44.

The square root of 645509087 is about 25406.8708620326. The cubic root of 645509087 is about 864.2395164824.

It can be divided in two parts, 64550 and 9087, that added together give a palindrome (73637).

The spelling of 645509087 in words is "six hundred forty-five million, five hundred nine thousand, eighty-seven".