661615012 has 6 divisors (see below), whose sum is σ = 1157826278. Its totient is φ = 330807504.

The previous prime is 661615007. The next prime is 661615013. The reversal of 661615012 is 210516166.

It can be written as a sum of positive squares in only one way, i.e., 619312996 + 42302016 = 24886^2 + 6504^2 .

It is not an unprimeable number, because it can be changed into a prime (661615013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82701873 + ... + 82701880.

Almost surely, 2^661615012 is an apocalyptic number.

It is an amenable number.

661615012 is a deficient number, since it is larger than the sum of its proper divisors (496211266).

661615012 is a wasteful number, since it uses less digits than its factorization.

661615012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165403757 (or 165403755 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 661615012 is about 25721.8780807312. The cubic root of 661615012 is about 871.3683544677.

The spelling of 661615012 in words is "six hundred sixty-one million, six hundred fifteen thousand, twelve".