645566089 has 4 divisors (see below), whose sum is σ = 737789824. Its totient is φ = 553342356.

The previous prime is 645566081. The next prime is 645566101. The reversal of 645566089 is 980665546.

It is a happy number.

645566089 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 645566089 - 2³ = 645566081 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645566081) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46111857 + ... + 46111870.

It is an arithmetic number, because the mean of its divisors is an integer number (184447456).

Almost surely, 2^645566089 is an apocalyptic number.

It is an amenable number.

645566089 is a deficient number, since it is larger than the sum of its proper divisors (92223735).

645566089 is an equidigital number, since it uses as much as digits as its factorization.

645566089 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92223734.

The product of its (nonzero) digits is 1555200, while the sum is 49.

The square root of 645566089 is about 25407.9926204334. The cubic root of 645566089 is about 864.2649547666.

The spelling of 645566089 in words is "six hundred forty-five million, five hundred sixty-six thousand, eighty-nine".