645224237 has 16 divisors (see below), whose sum is σ = 747256320. Its totient is φ = 545701632.

The previous prime is 645224227. The next prime is 645224263. The reversal of 645224237 is 732422546.

It is not a de Polignac number, because 645224237 - 2¹⁸ = 644962093 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 645224197 and 645224206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645224227) 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 15 ways as a sum of consecutive naturals, for example, 187343 + ... + 190755.

It is an arithmetic number, because the mean of its divisors is an integer number (46703520).

Almost surely, 2^645224237 is an apocalyptic number.

It is an amenable number.

645224237 is a deficient number, since it is larger than the sum of its proper divisors (102032083).

645224237 is a wasteful number, since it uses less digits than its factorization.

645224237 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3772.

The product of its digits is 80640, while the sum is 35.

The square root of 645224237 is about 25401.2644763996. The cubic root of 645224237 is about 864.1123740190.

The spelling of 645224237 in words is "six hundred forty-five million, two hundred twenty-four thousand, two hundred thirty-seven".