661612 has 12 divisors (see below), whose sum is σ = 1323280. Its totient is φ = 283536.

The previous prime is 661607. The next prime is 661613. The reversal of 661612 is 216166.

661612 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (661613) 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, 11787 + ... + 11842.

2⁶⁶¹⁶¹² is an apocalyptic number.

It is an amenable number.

661612 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661612 is a wasteful number, since it uses less digits than its factorization.

661612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23640 (or 23638 counting only the distinct ones).

The product of its digits is 432, while the sum is 22.

The square root of 661612 is about 813.3953528267. The cubic root of 661612 is about 87.1367032165.

Adding to 661612 its reverse (216166), we get a palindrome (877778).

The spelling of 661612 in words is "six hundred sixty-one thousand, six hundred twelve".