645009023 has 8 divisors (see below), whose sum is σ = 651146496. Its totient is φ = 638890200.

The previous prime is 645008999. The next prime is 645009037. The reversal of 645009023 is 320900546.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 645009023 - 2¹⁶ = 644943487 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645000023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70490 + ... + 79112.

It is an arithmetic number, because the mean of its divisors is an integer number (81393312).

Almost surely, 2^645009023 is an apocalyptic number.

645009023 is a deficient number, since it is larger than the sum of its proper divisors (6137473).

645009023 is a wasteful number, since it uses less digits than its factorization.

645009023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9325.

The product of its (nonzero) digits is 6480, while the sum is 29.

The square root of 645009023 is about 25397.0278379184. The cubic root of 645009023 is about 864.0162886840.

Adding to 645009023 its reverse (320900546), we get a palindrome (965909569).

The spelling of 645009023 in words is "six hundred forty-five million, nine thousand, twenty-three".