661601212 has 6 divisors (see below), whose sum is σ = 1157802128. Its totient is φ = 330800604.

The previous prime is 661601203. The next prime is 661601267. The reversal of 661601212 is 212106166.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82700148 + ... + 82700155.

Almost surely, 2^661601212 is an apocalyptic number.

It is an amenable number.

661601212 is a deficient number, since it is larger than the sum of its proper divisors (496200916).

661601212 is a wasteful number, since it uses less digits than its factorization.

661601212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165400307 (or 165400305 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 661601212 is about 25721.6098252034. The cubic root of 661601212 is about 871.3622960769.

Adding to 661601212 its reverse (212106166), we get a palindrome (873707378).

The spelling of 661601212 in words is "six hundred sixty-one million, six hundred one thousand, two hundred twelve".