166521403534636 has 12 divisors (see below), whose sum is σ = 308554365373128. Its totient is φ = 78363013428032.

The previous prime is 166521403534631. The next prime is 166521403534693. The reversal of 166521403534636 is 636435304125661.

It is not an unprimeable number, because it can be changed into a prime (166521403534631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1224422084746 + ... + 1224422084881.

It is an arithmetic number, because the mean of its divisors is an integer number (25712863781094).

Almost surely, 2^{166521403534636} is an apocalyptic number.

It is an amenable number.

166521403534636 is a deficient number, since it is larger than the sum of its proper divisors (142032961838492).

166521403534636 is a wasteful number, since it uses less digits than its factorization.

166521403534636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2448844169648 (or 2448844169646 counting only the distinct ones).

The product of its (nonzero) digits is 27993600, while the sum is 55.

The spelling of 166521403534636 in words is "one hundred sixty-six trillion, five hundred twenty-one billion, four hundred three million, five hundred thirty-four thousand, six hundred thirty-six".