661613012 has 6 divisors (see below), whose sum is σ = 1157822778. Its totient is φ = 330806504.

The previous prime is 661612999. The next prime is 661613033. The reversal of 661613012 is 210316166.

It can be written as a sum of positive squares in only one way, i.e., 560931856 + 100681156 = 23684^2 + 10034^2 .

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, 82701623 + ... + 82701630.

It is an arithmetic number, because the mean of its divisors is an integer number (192970463).

Almost surely, 2^661613012 is an apocalyptic number.

It is an amenable number.

661613012 is a deficient number, since it is larger than the sum of its proper divisors (496209766).

661613012 is a wasteful number, since it uses less digits than its factorization.

661613012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165403257 (or 165403255 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 661613012 is about 25721.8392032918. The cubic root of 661613012 is about 871.3674764452.

Adding to 661613012 its reverse (210316166), we get a palindrome (871929178).

The spelling of 661613012 in words is "six hundred sixty-one million, six hundred thirteen thousand, twelve".