661636622106 has 16 divisors (see below), whose sum is σ = 1470303604800. Its totient is φ = 220545540684.

The previous prime is 661636622029. The next prime is 661636622107. The reversal of 661636622106 is 601226636166.

661636622106 is a `hidden beast` number, since 6 + 6 + 1 + 6 + 3 + 6 + 622 + 10 + 6 = 666.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (661636622107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6126264966 + ... + 6126265073.

It is an arithmetic number, because the mean of its divisors is an integer number (91893975300).

Almost surely, 2^661636622106 is an apocalyptic number.

661636622106 is an abundant number, since it is smaller than the sum of its proper divisors (808666982694).

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

661636622106 is a wasteful number, since it uses less digits than its factorization.

661636622106 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12252530050 (or 12252530044 counting only the distinct ones).

The product of its (nonzero) digits is 559872, while the sum is 45.

The spelling of 661636622106 in words is "six hundred sixty-one billion, six hundred thirty-six million, six hundred twenty-two thousand, one hundred six".