645425444203 has 4 divisors (see below), whose sum is σ = 645629244480. Its totient is φ = 645221643928.

The previous prime is 645425444197. The next prime is 645425444219. The reversal of 645425444203 is 302444524546.

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 645425444203 - 2¹⁷ = 645425313131 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 645425444203.

It is not an unprimeable number, because it can be changed into a prime (645425444303) 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, 101895388 + ... + 101901721.

It is an arithmetic number, because the mean of its divisors is an integer number (161407311120).

Almost surely, 2^645425444203 is an apocalyptic number.

645425444203 is a deficient number, since it is larger than the sum of its proper divisors (203800277).

645425444203 is a wasteful number, since it uses less digits than its factorization.

645425444203 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 203800276.

The product of its (nonzero) digits is 1843200, while the sum is 43.

Adding to 645425444203 its reverse (302444524546), we get a palindrome (947869968749).

The spelling of 645425444203 in words is "six hundred forty-five billion, four hundred twenty-five million, four hundred forty-four thousand, two hundred three".