206155420401666 has 16 divisors (see below), whose sum is σ = 418118035745088. Its totient is φ = 67750607643600.

The previous prime is 206155420401659. The next prime is 206155420401691. The reversal of 206155420401666 is 666104024551602.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 241966455445 + ... + 241966456296.

It is an arithmetic number, because the mean of its divisors is an integer number (26132377234068).

Almost surely, 2^{206155420401666} is an apocalyptic number.

206155420401666 is an abundant number, since it is smaller than the sum of its proper divisors (211962615343422).

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

206155420401666 is a wasteful number, since it uses less digits than its factorization.

206155420401666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 483932911817.

The product of its (nonzero) digits is 2073600, while the sum is 48.

The spelling of 206155420401666 in words is "two hundred six trillion, one hundred fifty-five billion, four hundred twenty million, four hundred one thousand, six hundred sixty-six".