661424212 has 12 divisors (see below), whose sum is σ = 1157718100. Its totient is φ = 330647616.

The previous prime is 661424209. The next prime is 661424213. The reversal of 661424212 is 212424166.

It can be written as a sum of positive squares in 2 ways, for example, as 6780816 + 654643396 = 2604^2 + 25586^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661424213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12664 + ... + 38512.

Almost surely, 2^661424212 is an apocalyptic number.

It is an amenable number.

661424212 is a deficient number, since it is larger than the sum of its proper divisors (496293888).

661424212 is a wasteful number, since it uses less digits than its factorization.

661424212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32250 (or 32248 counting only the distinct ones).

The product of its digits is 4608, while the sum is 28.

The square root of 661424212 is about 25718.1689083807. The cubic root of 661424212 is about 871.2845831588.

Adding to 661424212 its reverse (212424166), we get a palindrome (873848378).

The spelling of 661424212 in words is "six hundred sixty-one million, four hundred twenty-four thousand, two hundred twelve".