645242603 has 4 divisors (see below), whose sum is σ = 679202760. Its totient is φ = 611282448.

The previous prime is 645242579. The next prime is 645242623. The reversal of 645242603 is 306242546.

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 645242603 - 2⁶ = 645242539 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 645242603.

It is not an unprimeable number, because it can be changed into a prime (645242623) 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, 16980050 + ... + 16980087.

It is an arithmetic number, because the mean of its divisors is an integer number (169800690).

Almost surely, 2^645242603 is an apocalyptic number.

645242603 is a deficient number, since it is larger than the sum of its proper divisors (33960157).

645242603 is a wasteful number, since it uses less digits than its factorization.

645242603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33960156.

The product of its (nonzero) digits is 34560, while the sum is 32.

The square root of 645242603 is about 25401.6259912628. The cubic root of 645242603 is about 864.1205727900.

The spelling of 645242603 in words is "six hundred forty-five million, two hundred forty-two thousand, six hundred three".