166668220642 has 48 divisors (see below), whose sum is σ = 317793354912. Its totient is φ = 64825918080.

The previous prime is 166668220637. The next prime is 166668220657. The reversal of 166668220642 is 246022866661.

166668220642 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 508893 + ... + 769615.

It is an arithmetic number, because the mean of its divisors is an integer number (6620694894).

Almost surely, 2^166668220642 is an apocalyptic number.

166668220642 is a deficient number, since it is larger than the sum of its proper divisors (151125134270).

166668220642 is a wasteful number, since it uses less digits than its factorization.

166668220642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261343 (or 261336 counting only the distinct ones).

The product of its (nonzero) digits is 1990656, while the sum is 49.

The spelling of 166668220642 in words is "one hundred sixty-six billion, six hundred sixty-eight million, two hundred twenty thousand, six hundred forty-two".