661553612 has 6 divisors (see below), whose sum is σ = 1157718828. Its totient is φ = 330776804.

The previous prime is 661553611. The next prime is 661553617. The reversal of 661553612 is 216355166.

661553612 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (661553611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82694198 + ... + 82694205.

It is an arithmetic number, because the mean of its divisors is an integer number (192953138).

Almost surely, 2^661553612 is an apocalyptic number.

It is an amenable number.

661553612 is a deficient number, since it is larger than the sum of its proper divisors (496165216).

661553612 is a wasteful number, since it uses less digits than its factorization.

661553612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165388407 (or 165388405 counting only the distinct ones).

The product of its digits is 32400, while the sum is 35.

The square root of 661553612 is about 25720.6845165520. The cubic root of 661553612 is about 871.3413983723.

The spelling of 661553612 in words is "six hundred sixty-one million, five hundred fifty-three thousand, six hundred twelve".