21666035055166 has 8 divisors (see below), whose sum is σ = 32820825380904. Its totient is φ = 10725759928200.

The previous prime is 21666035055163. The next prime is 21666035055169. The reversal of 21666035055166 is 66155053066612.

It is an interprime number because it is at equal distance from previous prime (21666035055163) and next prime (21666035055169).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21666035055163) 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, 53628799440 + ... + 53628799843.

It is an arithmetic number, because the mean of its divisors is an integer number (4102603172613).

Almost surely, 2^{21666035055166} is an apocalyptic number.

21666035055166 is a deficient number, since it is larger than the sum of its proper divisors (11154790325738).

21666035055166 is a wasteful number, since it uses less digits than its factorization.

21666035055166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107257599386.

The product of its (nonzero) digits is 5832000, while the sum is 52.

The spelling of 21666035055166 in words is "twenty-one trillion, six hundred sixty-six billion, thirty-five million, fifty-five thousand, one hundred sixty-six".