645538683 has 6 divisors (see below), whose sum is σ = 860776924. Its totient is φ = 430329784.

The previous prime is 645538681. The next prime is 645538703. The reversal of 645538683 is 386835546.

It is not a de Polignac number, because 645538683 - 2¹ = 645538681 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645538681) 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 5 ways as a sum of consecutive naturals, for example, 36673 + ... + 51341.

Almost surely, 2^645538683 is an apocalyptic number.

645538683 is a deficient number, since it is larger than the sum of its proper divisors (215238241).

645538683 is an frugal number, since it uses more digits than its factorization.

645538683 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29341 (or 14672 counting only the distinct ones).

The product of its digits is 2073600, while the sum is 48.

The square root of 645538683 is about 25407.4532962279. The cubic root of 645538683 is about 864.2527244771.

Multiplying 645538683 by its sum of digits (48), we get a square (30985856784 = 176028²).

The spelling of 645538683 in words is "six hundred forty-five million, five hundred thirty-eight thousand, six hundred eighty-three".