645144212 has 12 divisors (see below), whose sum is σ = 1132203156. Its totient is φ = 321657600.

The previous prime is 645144197. The next prime is 645144217. The reversal of 645144212 is 212441546.

It can be written as a sum of positive squares in 2 ways, for example, as 295977616 + 349166596 = 17204^2 + 18686^2 .

It is a super-2 number, since 2×645144212² = 832422108554201888, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645144217) 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, 227039 + ... + 229862.

It is an arithmetic number, because the mean of its divisors is an integer number (94350263).

Almost surely, 2^645144212 is an apocalyptic number.

It is an amenable number.

645144212 is a deficient number, since it is larger than the sum of its proper divisors (487058944).

645144212 is a wasteful number, since it uses less digits than its factorization.

645144212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 457258 (or 457256 counting only the distinct ones).

The product of its digits is 7680, while the sum is 29.

The square root of 645144212 is about 25399.6892106970. The cubic root of 645144212 is about 864.0766482212.

Adding to 645144212 its reverse (212441546), we get a palindrome (857585758).

The spelling of 645144212 in words is "six hundred forty-five million, one hundred forty-four thousand, two hundred twelve".