645385423 has 4 divisors (see below), whose sum is σ = 646779808. Its totient is φ = 643991040.

The previous prime is 645385421. The next prime is 645385453. The reversal of 645385423 is 324583546.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 645385423 - 2¹ = 645385421 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645385421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 696498 + ... + 697423.

It is an arithmetic number, because the mean of its divisors is an integer number (161694952).

Almost surely, 2^645385423 is an apocalyptic number.

645385423 is a deficient number, since it is larger than the sum of its proper divisors (1394385).

645385423 is a wasteful number, since it uses less digits than its factorization.

645385423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1394384.

The product of its digits is 345600, while the sum is 40.

The square root of 645385423 is about 25404.4370730784. The cubic root of 645385423 is about 864.1843237963.

The spelling of 645385423 in words is "six hundred forty-five million, three hundred eighty-five thousand, four hundred twenty-three".